fix(desktop): emit camelCase config-write payload fields

[Chessing234]

Fixes #6015.

ConfigWriteMechanism is internally tagged and carried only rename_all = "camelCase". On an internally tagged enum that renames the variants, never the variants' fields, so the payload went out snake_case:

{"type":"respawnWithEnvVar","env_key":"K"}
{"type":"acpSetConfigOption","config_id":"c"}
{"type":"acpSetSessionModel"}
{"type":"gooseNativeConfigWrite","config_key":"g"}
{"type":"readOnly"}

against envKey / configId / configKey in desktop/src/shared/api/types.ts:615-620. That output is a probe run of the real module before the fix, not a reading of the code.

What makes it read as correct is the asymmetry: the variant names rename fine, so the type discriminant and every switch (writeVia.type) behave; and the enclosing NormalizedField's own fields (writeVia, overriddenValue, isRequired) rename fine too, because rename_all does apply to struct fields. Only the variant's field is wrong.

Adding rename_all_fields = "camelCase" fixes it. rename_all_fields appeared zero times in desktop/src-tauri before this.

Severity, stated plainly: latent, not currently user-visible. Nothing in desktop/src/** reads .envKey/.configId/.configKey off a writeVia — AgentConfigPanel.tsx is the only RuntimeConfigSurface consumer and never touches the field, and no Rust code deserializes the type either. The write-back path these fields exist for is not wired yet. The hazard is for whoever wires it: invokeTauri<T> is an unchecked cast, so they get undefined with a green tsc.

I also carried the attribute onto ConfigFieldType. Its only payload field is options, single-word, so that half is not a fix — it is the attribute the next multi-word field would silently need.

One divergence from the issue's suggested step 3: the 20 e2eBridge.ts sites already emit camelCase, and camelCase is the contract, so they are correct as written — changing them would have been wrong. What they lacked was provenance, since agreeing with api/types.ts while the backend emitted something else is exactly what let this sit. They now name the Rust test that pins the bytes.

Tests (wire_format_tests, 4 cases, whole-value not key-set — a key-set assertion still passes when a variant name regresses):

• every variant against the TypeScript spelling;
• the nested NormalizedField, which is the shape the renderer actually receives;
• a camelCase round-trip plus an assertion that the old env_key spelling is now rejected, so a revert cannot quietly keep deserializing;
• ConfigFieldType::Enum.

Removing rename_all_fields again turns three of the four red.

Verified locally: full Tauri library suite 2444 passed / 15 ignored / 0 failed; cargo clippy --manifest-path desktop/src-tauri/Cargo.toml --workspace --all-targets -- -D warnings clean; cargo fmt --manifest-path desktop/src-tauri/Cargo.toml --all -- --check; in desktop/: pnpm typecheck, pnpm check, pnpm test 4954 passed; git diff --check. Not run: the app itself — there is no UI path to this field yet, which is the same reason the bug is latent.

[themiguelamador]

I found and fixed two minor review issues:

• P3 — Keep the patch scoped to the broken wire contract. rename_all_fields was also added to ConfigFieldType, but its only payload field (options) is already a single camel-case word. That change has no effect today and silently chooses serialization behavior for future fields unrelated to this bug, so I removed it and its non-regression test.
• P3 — Assert JSON semantics, not serializer property order. The new tests compared exact serialized strings, coupling the contract tests to object-key order even though JSON object order is not semantic. I changed them to whole-value serde_json::Value comparisons, which still verify every key and value (including nested fields) without overconstraining the encoder.

Fix branch: https://github.com/Complear/buzz/tree/review/pr-6062-fix
Commit: d0f57d1de

Validation: full Tauri library suite (2,443 passed, 15 ignored), strict Tauri workspace/all-target clippy, focused wire-format tests, cargo fmt, desktop typecheck, full desktop checks, and git diff --check all passed. The desktop checks reported only the four pre-existing advisory Biome diagnostics outside this PR.

[Chessing234]

Both applied, one commit each (3ae0add, 935d6a4). (Complear/buzz 404s, so written from your description.)

P3 — scope. Verified inert before removing it: ConfigFieldType's other three variants are unit variants, and api/types.ts declares the enum as { type: "enum"; options: string[] }, so rename_all_fields changes no byte the renderer sees today. Removed it and its test — that test was explicitly a shape pin, not a non-regression, and nothing it asserted could have failed. ConfigWriteMechanism keeps the attribute, where it is the fix.

Worth stating the trade-off you're accepting, since it's the same footgun this PR exists to close: a future multi-word field on ConfigFieldType will serialize snake_case and invokeTauri<T>'s unchecked cast won't catch it. I agree that's not this patch's job to pre-empt.

P3 — JSON semantics. Agreed, key order isn't semantic. The two serialization tests now compare whole serde_json::Values built with json!, which still catches a renamed variant or field. The round-trip test keeps its string literals deliberately: there the exact input bytes are the point, since it asserts the renderer's shape is accepted and the pre-fix snake_case spelling isn't.

Verification: full Tauri lib suite (2,443 passed, 15 ignored), strict workspace/all-target clippy, and cargo fmt --check.

[ravarora2]

🤖 LGTM at reviewed head 935d6a40fda7267d76460af32090b4e236b5b4b6.

This is a narrow, correct serialization-contract fix: it makes the nested Rust fields (env_key, config_id, and config_key) serialize with the camelCase names TypeScript already expects, without changing the operation discriminants, surrounding shape, configuration values, or write authority.

Local verification passed the full Desktop JavaScript suite (4,954 tests), full Desktop Tauri suite (2,544 passed, 16 ignored), and causal mutations that restore the original bug when the Serde attribute is removed. No merge blockers found in the code review. GitHub CI is still finishing at the time of this comment.

[ravarora2]

lgtm, will wait for owners for final merge