fix(observability): stable fingerprints for DB-connection errors and legible Failed-query titles

[kojiwakayama]

Refs VERYFRONT-API-8, VERYFRONT-STUDIO-63.

Problem

During DB/pgbouncer outages (Aug 5 19:02-20:19 UTC and Aug 12), two Sentry-reporting artifacts made one incident look like many unrelated issues:

1. PostgresError events fingerprint by a spurious, scope-inherited transaction, splitting a single pooler outage across issues titled with random routes.
2. DrizzleQueryError messages are Failed query: ${query}\nparams: ${params}. Multi-line sql` templates open with a newline, so Sentry titles render as a blank Failed query:; single-line query-builder SQL renders the whole statement plus the params: section into the title.
3. postgres.js surfaces every client-side connection failure as a plain Error with a write <CODE> <host>:<port> shape. Those errors should group with DB connection noise without broadening server pgbouncer code matching.

Fix

1. PostgresError values whose message ends with a pgbouncer connection code ((server_login_retry), (query_wait_timeout)) get the stable fingerprint [<service>, "veryfront-db-error", <code>]. Ordinary errors that only quote a code name retain their normal service fingerprint.
2. Plain Error values get the database fingerprint when they match the postgres.js Errors.connection() message shape, for all four codes that function emits: CONNECTION_CLOSED, CONNECTION_DESTROYED, CONNECTION_ENDED, CONNECT_TIMEOUT. Unrelated errors containing those tokens keep their normal service fingerprint.
3. Failed-query values collapse SQL whitespace and cap the statement head at 200 characters, for both the newline-leading multi-line template shape and the single-line query-builder shape. A following params: section is removed before title construction so query parameters cannot enter the issue title.
4. Exception text is redacted before Failed-query normalization and truncation, so credential-shaped values crossing the cutoff cannot leave unredacted fragments.
5. Failed-query titles replace single-quoted (including escaped), dollar-quoted, decimal or exponent numeric (including digit separators), and PostgreSQL radix integer literals with ?. Double-quoted identifiers and $1 bind parameters remain legible for useful issue grouping.
6. Failed-query titles replace line and block comments with ? after quoted-token recognition, so customer context in comments cannot enter issue titles while quoted identifiers, strings, dollar strings, and bind parameters retain their existing treatment.

Fingerprint shape: service attribution is kept

DB-connection events fingerprint as [<service>, "veryfront-db-error", <code>], not ["veryfront-db-error", <code>]. Every other event in this file leads with the service name, and Sentry issue ownership, alert routing, and team assignment are all per-service - collapsing an api outage and a renderer outage into a single issue would hand one team another team's events. The fragmentation this PR exists to fix is per-route (dozens of issues per service), and that is fully resolved by the shared veryfront-db-error element regardless of the leading service name. The extra collapse across services is a much smaller win and is available at query time via the service.name tag.

SQL lexer bounds

• The unrecognized dollar-quote fallback requires a tag-shaped delimiter with no whitespace, quotes, or further $, but imposes no length cap because PostgreSQL does not impose one. A delimiter-shaped $ is opened only at a token boundary, so dollar signs after ASCII or non-Latin identifier characters stay part of the identifier. $ itself remains a boundary so adjacent dollar-quoted literals are both redacted.
• An unterminated double-quoted identifier now emits ? rather than the remainder of the query verbatim. Terminated double-quoted identifiers are still preserved on purpose - they are schema, not data, and redacting them would destroy grouping. That intent is now recorded in a source comment.

Testing

Red-green regressions cover pgbouncer PostgresError grouping, quoted and mid-message code-name false positives, all four postgres.js plain-Error connection codes plus an unknown-code negative, an unrelated plain CONNECTION_CLOSED error, parameter exclusion from Failed-query titles, single-line query-builder SQL normalization (fixture taken byte-for-byte from a real drizzle-orm@0.45.1 .toSQL() message), same-line multi-line template normalization, the single-line 200-character cap, newline-leading SQL normalization, quoted and dollar-quoted SQL literals, $-in-identifier and bare-$ lexer bounds, unterminated quoted identifiers, decimal integer, fractional, and exponent digit separators, PostgreSQL radix numeric literals, preserved identifiers and bind parameters, line and nested block comment redaction, quoted comment-marker precedence, long literal redaction, and untouched unrelated errors.

Verified at the current head with 56 focused Sentry extension tests (45 in policy.test.ts), targeted format, lint, typecheck, and diff checks. Red-green review regressions cover unlimited dollar tags, ASCII and non-Latin identifier boundaries, adjacent dollar literals, and conservative handling of backslash-escaped ordinary strings when the event does not expose the PostgreSQL compatibility setting.

Summary by CodeRabbit

• Bug Fixes

  • Improved Sentry grouping for PostgreSQL and PostgreSQL.js connection failures.
  • Reduced misleading grouping for unrelated errors by preserving standard fingerprints.
  • Sanitized failed SQL details by removing sensitive parameters, literals, comments, and excess whitespace.
  • Limited captured query text to 200 characters for clearer error details.

• Tests

  • Added comprehensive coverage for database error detection, false positives, fingerprinting, and SQL sanitization edge cases.

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---

📝 Walkthrough

Walkthrough

The Sentry policy now groups recognized database connection errors and sanitizes Drizzle failed-query exception values. SQL literals, comments, parameters, and excess whitespace are normalized before title construction, with a 200-character limit.

Changes

Sentry policy updates

Layer / File(s)	Summary
Database error fingerprinting extensions/ext-observability-sentry/src/policy.ts, extensions/ext-observability-sentry/src/policy.test.ts	The event shape includes an optional exception type. Recognized PostgreSQL, pgbouncer, and PostgreSQL.js connection errors receive database-specific fingerprints. Other events retain service-based fingerprints. Tests cover grouping and false positives.
Failed-query sanitization extensions/ext-observability-sentry/src/policy.ts, extensions/ext-observability-sentry/src/policy.test.ts	Failed-query values remove parameters, SQL literals, comments, and excess whitespace. The resulting title is limited to 200 characters. Tests cover quoted and numeric literals, dollar quotes, comments, edge cases, and non-query errors.

Estimated code review effort: 4 (Complex) | ~45 minutes

Merge Risk: ⚪ Minimal · up to 97417

This change stabilizes database-error grouping and makes failed-query titles readable while removing parameter, literal, and comment content; leading-whitespace and newline normalization are covered, so no actionable merge-blocking risk remains beyond normal checks.

🚥 Pre-merge checks | ✅ 5

✅ Passed checks (5 passed)

Check name	Status	Explanation
Description Check	✅ Passed	Check skipped - CodeRabbit’s high-level summary is enabled.
Title check	✅ Passed	The title clearly summarizes the main changes: stable database-connection fingerprints and readable failed-query titles.
Docstring Coverage	✅ Passed	No functions found in the changed files to evaluate docstring coverage. Skipping docstring coverage check.
Linked Issues check	✅ Passed	Check skipped because no linked issues were found for this pull request.
Out of Scope Changes check	✅ Passed	Check skipped because no linked issues were found for this pull request.

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📦 Client bundle boundary

Entrypoint	Modules	Source size	Server leaks
src/index.client.ts	454	3065 KiB	⚠️ 39 known

A server module in a client graph aborts hydration in the browser. New leaks fail CI; known leaks are tracked in scripts/lint/client-bundle-baseline.json to burn down.

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[kwakayama]

@coderabbitai review

This PR is now out of draft. The previous CodeRabbit pass was skipped ("Review skipped: draft pull request") and the last full pass predates the fix commit. Please review current head 541375dba, which reworked normalizeFailedQueryValue (removed the leading-newline gate), widened postgres.js connection-code coverage, and changed the dollar-quote fallback in the SQL lexer.

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🧩 Analysis chain

🏁 Script executed:

#!/bin/bash
set -euo pipefail

echo '== Current HEAD =='
git rev-parse HEAD
git status --short
echo

echo '== Changed files against PR base candidate =='
git diff --stat HEAD^..HEAD
git diff --name-only HEAD^..HEAD
echo

echo '== policy.ts outline =='
ast-grep outline extensions/ext-observability-sentry/src/policy.ts --items all --type function,interface,type
echo

echo '== policy.test.ts outline =='
ast-grep outline extensions/ext-observability-sentry/src/policy.test.ts --items all --type function
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echo '== Relevant implementation symbols =='
rg -n -C 8 --type ts \
  'normalizeFailedQueryValue|POSTGRES_JS_CONNECTION_ERROR_PATTERN|DB_ERROR_FINGERPRINT|findQuotedSqlTokenEnd|SQL_DOLLAR_QUOTE|prepareSentryEvent' \
  extensions/ext-observability-sentry/src/policy.ts
echo

echo '== Relevant test cases =='
rg -n -C 5 --type ts \
  'Failed query|CONNECTION_(ENDED|DESTROYED|CLOSED)|CONNECT_TIMEOUT|dollar|unterminated|fingerprint|params:' \
  extensions/ext-observability-sentry/src/policy.test.ts
echo

echo '== Current patch =='
git diff --find-renames HEAD^..HEAD -- \
  extensions/ext-observability-sentry/src/policy.ts \
  extensions/ext-observability-sentry/src/policy.test.ts

Length of output: 1978

---

🏁 Script executed:

#!/bin/bash
set -euo pipefail

echo '== Branch and available refs =='
git branch --show-current
git branch -a --no-color | sed -n '1,120p'
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echo '== policy.ts outline =='
ast-grep outline extensions/ext-observability-sentry/src/policy.ts --items all
echo

echo '== policy.test.ts outline =='
ast-grep outline extensions/ext-observability-sentry/src/policy.test.ts --items all
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echo '== policy.ts relevant implementation =='
rg -n --type ts \
  'normalizeFailedQueryValue|POSTGRES_JS_CONNECTION_ERROR_PATTERN|DB_ERROR_FINGERPRINT|findQuotedSqlTokenEnd|SQL_DOLLAR_QUOTE|prepareSentryEvent' \
  extensions/ext-observability-sentry/src/policy.ts
sed -n '1,420p' extensions/ext-observability-sentry/src/policy.ts
echo

echo '== policy.test.ts relevant test locations =='
rg -n --type ts \
  'Failed query|CONNECTION_(ENDED|DESTROYED|CLOSED)|CONNECT_TIMEOUT|dollar|unterminated|fingerprint|params:' \
  extensions/ext-observability-sentry/src/policy.test.ts
sed -n '1,620p' extensions/ext-observability-sentry/src/policy.test.ts
echo

echo '== Final commit patch =='
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  extensions/ext-observability-sentry/src/policy.ts \
  extensions/ext-observability-sentry/src/policy.test.ts

Length of output: 58148

---

@kwakayama I found one issue in the current head.

P1 — Preserve $tag$ sequences inside unquoted identifiers

findDollarQuotedSqlTokenEnd accepts a recognized delimiter at every $. PostgreSQL permits $ in an unquoted identifier. If a $tag$ sequence follows an identifier character, it is part of that identifier. It is not a dollar-quoted literal.

For example, a query that contains column$tag$ can cause the lexer to redact the remaining query. If a later $tag$ exists, the lexer redacts through that later sequence. If no later delimiter exists, it redacts to the end of the query.

Check the opening delimiter boundary before calling findDollarQuotedSqlTokenEnd. The opening $ must not follow SQL_IDENTIFIER_CHAR_PATTERN. Add tests for both a terminated-looking identifier sequence and an identifier sequence without a later delimiter.

The existing col$a test does not cover this case.

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[kwakayama]

Codex reviewed 541375dba and raised two findings on the dollar-quote fallback. Both were real — one was a genuine leak I introduced in that commit. Fixed in 9f4e00cae.

1. The {1,63} tag cap was a leak (Codex P2, valid)

I bounded the unrecognized dollar-quote tag to 1-63 characters in 541375dba, reasoning that a real tag is short. That was wrong on its own terms and it leaked.

PostgreSQL's scanner rule is:

dolq_start   [A-Za-z\200-\377_]
dolq_cont    [A-Za-z\200-\377_0-9]
dolqdelim    \$({dolq_start}{dolq_cont}*)?\$

\200-\377 means any high byte, so non-ASCII tags — emoji included — are valid PostgreSQL, and the rule carries no length limit. My 63-character bound therefore rejected legal tags, and a rejected tag falls through to being emitted verbatim.

Reproduced on 541375dba:

IN : Failed query: select $<64x 😀>$Alice Smith$<64x 😀>$ from t
OUT: Failed query: select $😀😀…(64)…😀$Alice Smith$😀😀…   <- payload verbatim in the title

IN : Failed query: select $<63x 😀>$Alice Smith$<63x 😀>$ from t
OUT: Failed query: select ? from t                          <- one emoji shorter, redacted

A 63-emoji tag redacted and a 64-emoji tag leaked. That is exactly the arbitrary-cliff failure Codex described.

Fix: the cap is gone — /^\$[^\s'"$]+\$/u. The cap was never what stopped col$a from swallowing the query; the character class was. Removing the bound keeps every earlier regression fixed and closes the leak:

64-emoji tag                                    -> Failed query: select ? from t
select col$a, 'secret@x.test' as e, other$b     -> Failed query: select col$a, ? as e, other$b from t
select a, $ , 'secret@x.test', $1 from t        -> Failed query: select a, $ , ?, $1 from t

2. Token boundary before a dollar quote (Codex P2, valid)

col$tag$inner$tag$ was being read as identifier col followed by a literal, collapsing the title to col? and destroying the query shape. PostgreSQL disagrees: $ is ident_cont but not ident_start, and flex takes the longest match from the earliest position, so the whole run is one identifier.

Fix: refuse to open a dollar quote when the preceding character is [A-Za-z0-9_].

IN : Failed query: select col$tag$inner$tag$, other from t where id = $1
OUT: Failed query: select col$tag$inner$tag$, other from t where id = $1

The one subtlety, and why the obvious version of this fix is wrong. The file already has isSqlStringPrefixBoundary, and reusing it here looks natural. It is a leak. Its class is [A-Za-z0-9_$] — it includes $ — so after consuming one dollar-quoted literal, the next adjacent one is preceded by $, fails the check, and is emitted raw. Measured, with isSqlStringPrefixBoundary wired into the $ branch:

IN : Failed query: select $$first@example.test$$$$second@example.test$$ from t
OUT: Failed query: select ?$$second@example.test$$ from t     <- second literal leaks

So the new predicate is deliberately a different character class that omits $, and there is now a regression test pinning the adjacent-literal case:

IN : Failed query: select $$first@example.test$$$$second@example.test$$ from "orders"
OUT: Failed query: select ?? from "orders"

Worth a human eye: finding 2 converts over-redaction into identifier preservation. col$tag$inner$tag$ is now emitted whole. That is correct per PostgreSQL and consistent with this file's existing deliberate choice to preserve double-quoted identifiers verbatim (they are schema, not data) — but if raw interpolation of customer data into an identifier position is considered in scope, this is the line to revisit. Interpolated data in a value position is unaffected: it is either a quoted literal (redacted) or in params: (stripped).

Evidence

Red before, on 541375dba with the new fixtures added and policy.ts untouched:

FAILED | 41 passed | 2 failed

policy redacts dollar-quoted literals whose tag is longer than an identifier limit
policy treats a dollar sign after an identifier character as part of the identifier

The third new test, policy redacts both halves of adjacent dollar-quoted literals, passes on both trees by design — it exists to fail if anyone later reaches for isSqlStringPrefixBoundary here.

Green after: ok | 54 passed | 0 failed across the extension (43 in policy.test.ts).

deno fmt --check, deno lint, deno check clean on both files; full husky pre-push suite run on push, no --no-verify.

Re: CodeRabbit's leading-whitespace thread

Already fixed on this branch and the thread is resolved and outdated, but recording the evidence since it was raised against 62b01e9c3. policy.ts collapses and trims before slicing, and computes truncated from the normalized value:

400 leading spaces        -> Failed query: select "id" from "users"   (head intact, no truncation)
normalized exactly 200    -> no "…" appended
normalized exactly 201    -> "…" appended

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Inline comments:
In `@extensions/ext-observability-sentry/src/policy.ts`:
- Around line 243-246: Update the ordinary single-quoted string handling in the
query redaction logic around findQuotedSqlTokenEnd to recognize
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[kwakayama]

CodeRabbit's one actionable finding on 9f4e00cae was real. Fixed in 97417efcd — but not the way it suggested, because the suggested change reopens a leak Codex flagged earlier in this same PR.

Heads-up on 4cfabad98. That commit landed while I was preparing this one and applies CodeRabbit's suggestion literally (allowBackslashEscapes: true). Measured against the real commit, it closes the standard_conforming_strings = off hole and reopens the default-configuration one:

4cfabad98:  select '\', 'customer@example.test' from orders
         -> Failed query: select ?customer@example.test?      <- leaks under scs = on (the default)

I rebased on top of it rather than reverting it — its two other changes are good and are kept (the \P{ASCII} widening of the identifier class, and the non-Latin 名$tag$ test). I replaced only the one line, and adjusted one expectation in its new test from select ? from "orders" to select ?; that test's includes(...) === false privacy assertion is untouched and still passes.

The finding is valid

Confirmed by running the branch:

IN : Failed query: select 'safe\' customer@example.test' from orders
OUT: Failed query: select ? customer@example.test?          <- address in the title

Under standard_conforming_strings = off (with backslash_quote permitting it) that is one literal, so closing it at the \' emits the rest of the statement verbatim.

Why the literal suggestion is not the fix

The suggestion is to set allowBackslashEscapes on the ordinary-string branch. That is exactly what this PR already removed, at Codex's request, in review comment 3787867930:

Parse backslashes according to the string prefix — when standard_conforming_strings is enabled and an ordinary SQL literal ends with a backslash before another literal, this branch incorrectly treats the first literal's closing quote as escaped. select '\', 'customer@example.test' is normalized to select ?customer@example.test?.

So the two readings leak in opposite configurations:

	scs = on (default)	scs = off
backslash escapes off (before this commit)	correct	leaks
backslash escapes on (suggested)	leaks	correct

standard_conforming_strings is not in the error message, and it is not knowable from the exception value. Flipping the flag would trade a leak in a non-default configuration for a leak in the default one.

What I did instead — fail safe on ambiguity only

The two readings only diverge when an odd run of backslashes immediately precedes a candidate terminator. An even run ('public\\') closes at the same place under both settings, so it stays fully parsed and legible.

On an odd run the extent is genuinely ambiguous, so the scanner stops and the caller redacts the remainder rather than guessing:

scs=off  select 'safe\' customer@example.test' from orders   -> Failed query: select ?
scs=on   select '\', 'customer@example.test' from orders     -> Failed query: select ?
even     select 'public\\' 'customer@example.test' from t    -> Failed query: select ? ? from t

No leak under either setting. The cost is over-redaction of the scs=on odd-backslash case, which previously rendered as select ?, ? — an acceptable trade, since the construct is ambiguous by definition and this file's failure mode should be over-redaction, not under. E'...' literals are unaffected: they define backslash escaping regardless of the server setting, and keep their existing handling.

Worth noting for context: standard_conforming_strings has defaulted to on since PostgreSQL 9.1, postgres.js does not change it, and PostgreSQL 19 removes the ability to set it off at all. So the newly-closed hole was narrow — but it was a hole, and the fix costs almost nothing.

Evidence

Red before, fixture added on 9f4e00cae with policy.ts untouched:

FAILED | 44 passed | 1 failed
policy redacts the remainder when a backslash makes a string literal's extent ambiguous

The companion test policy keeps parsing when an even backslash run leaves the literal unambiguous passes on both trees by design — it fails if anyone later makes the bail-out unconditional.

Green after: ok | 58 passed | 0 failed (47 in policy.test.ts). The even-backslash test (renamed to policy keeps SQL string boundaries around pairs of backslashes in 4cfabad98) still passes, so the E'...' contract is intact.

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@codex review

[kwakayama]

Codex's P2 on 4cfabad98 — "Redact both interpretations of ordinary backslashes" — is already fixed by 97417efcd, which was pushed two minutes later. No action needed on it.

It reached the same conclusion independently, with the same example:

select '\', '<CUSTOMER_DATA>' is normalized with <CUSTOMER_DATA> still visible ... the new boundary test covers only the two-backslash form. Conservatively redact through the closures from both possible interpretations instead of selecting only the compatibility-string interpretation.

That is what 97417efcd implements. The two readings diverge only on an odd backslash run before a candidate terminator, so that case now bails out and the remainder is redacted; an even run stays fully parsed:

scs=off  select 'safe\' customer@example.test' from orders   -> Failed query: select ?
scs=on   select '\', 'customer@example.test' from orders     -> Failed query: select ?
even     select 'public\\' 'customer@example.test' from t    -> Failed query: select ? ? from t

Codex's note that the boundary test "covers only the two-backslash form" is also addressed: 97417efcd adds policy redacts the remainder when a backslash makes a string literal's extent ambiguous for the single-backslash case, alongside the even-run test.

Worth flagging for the record: CodeRabbit reviewed 4cfabad98 and endorsed it — "The conservative handling is appropriate because the Sentry event does not provide standard_conforming_strings" — because 4cfabad98 implements CodeRabbit's own suggestion. It did not notice that the suggestion trades the scs = off leak for an scs = on one, and scs = on is the default. Codex caught it. Two bots, opposite conclusions on the same line; the measured behaviour is what settled it.

[chatgpt-codex-connector]

💡 Codex Review

Here are some automated review suggestions for this pull request.

Reviewed commit: 97417efcd8

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[kojiwakayama]

Addressed the exact-head Unicode dollar-tag finding in bae1b95 with a red-green privacy regression. Verification: 59 extension tests pass; focused format, lint, typecheck, and diff checks pass. @codex review

[chatgpt-codex-connector]

Codex Review: Didn't find any major issues. 🚀

Reviewed commit: bae1b95cb2

ℹ️ About Codex in GitHub

Your team has set up Codex to review pull requests in this repo. Reviews are triggered when you

• Open a pull request for review
• Mark a draft as ready
• Comment "@codex review".

If Codex has suggestions, it will comment; otherwise it will react with 👍.

Codex can also answer questions or update the PR. Try commenting "@codex address that feedback".

[kwakayama]

Verification of the two dollar-quote findings against the current head bae1b95cb. Both threads are already resolved and outdated, so recording the substance here where it is readable rather than replying into a collapsed thread.

"Require a token boundary before dollar quotes" — fixed

$ is legal inside an unquoted PostgreSQL identifier after the first character, and flex prefers the longest match from the earliest position, so column$tag$ is one identifier rather than column followed by a delimiter. Both shapes behave correctly now:

IN : select column$tag$, 'secret@x.test' from t where note = $tag$inner$tag$
OUT: Failed query: select column$tag$, ? from t where note = ?

IN : select column$tag$, 'secret@x.test' from t          (no later delimiter)
OUT: Failed query: select column$tag$, ? from t

The identifier survives, the literal is redacted, and the no-closing-delimiter case does not run to end of query.

"Remove the 63-character dollar-tag cap" — fixed, and the cap was not justified

The cap is gone. I checked the premise rather than assuming it, because the obvious defence would have been "tags follow identifier rules, so 63 bytes is right".

PostgreSQL's manual, §4.1.2.4: "The tag, if any, of a dollar-quoted string follows the same rules as an unquoted identifier, except that it cannot contain a dollar sign." The NAMEDATALEN-1 truncation sentence appears in §4.1.1 for identifiers and is not restated for tags — tags are matched textually by the scanner as delimiters and are never stored as names, so nothing truncates them. There is no documented length limit on a dollar-quote tag.

So the cap rejected legal tags, and a rejected tag fell through to being emitted verbatim. Measured on the pre-fix tree, the boundary was exactly at 63:

63-emoji tag -> Failed query: select ? from t                    (redacted)
64-emoji tag -> Failed query: select $😀…(64)…$Alice Smith$😀…    (payload in the title)

Regression policy redacts dollar-quoted literals whose tag is longer than an identifier limit pins the 64-emoji case.

Non-regression sweep on bae1b95cb

Real dollar-quoting still redacts, including after punctuation:

$$secret@x.test$$                    -> select ?
$tag$secret@x.test$tag$              -> select ?
$é$secret@x.test$é$                  -> select ?
$😀$secret@x.test$😀$                -> select ?
$<64 emoji>$Alice Smith$<64 emoji>$  -> select ?
select a,$$secret@x.test$$           -> select a,?
select f($$secret@x.test$$)          -> select f(?)

Nothing legitimate is mangled:

select a from t where id = $1 and b = $10   -> unchanged
select col2, v1_2 from orders2 where id = $1 -> unchanged
select col$a, 'secret@x.test' as e, other$b, $ , $1 from t
  -> select col$a, ? as e, other$b, $ , $1 from t

The boundary check rejects a $ only when it directly follows an identifier character; $ itself is excluded from that class so adjacent literals such as $$a$$$$b$$ still parse as two dollar-quoted strings and both are redacted.

48 tests in policy.test.ts, 59 across the extension, all green.

[kojiwakayama]

Exact-head re-review for bae1b95: 93/100 merge confidence.

No blocking findings.

• Symptom checked: PostgreSQL dollar-quoted literal contents could reach a Sentry title when a legal high-byte tag character is also classified as whitespace by ECMAScript.
• Source: the fallback tag recognizer used ECMAScript whitespace semantics instead of PostgreSQL lexer whitespace.
• Consequence: customer-controlled SQL literal content could escape title sanitization for that tag class.
• Remedy verified: the fallback now excludes PostgreSQL ASCII whitespace explicitly while retaining the existing quote and dollar shape guards. The focused red regression covers U+00A0, all 59 extension tests pass, hosted checks are green, the exact-head Codex review is clean, and no review thread is unresolved.

Residual risk is limited to the heuristic SQL tokenizer by design. The new change narrows that risk without changing recognized identifier-tag behavior or non-query event handling.