backlog(B-0158): adopt .claude/rules pattern + carved-sentences-only constraint (Aaron 2026-05-01)

docs/BACKLOG.md

@@ -38,6 +38,7 @@ are closed (status: closed in frontmatter)._
 - [ ] **[B-0145](backlog/P1/B-0145-product-manager-role-research-to-predict-features-before-friction-aaron-2026-05-01.md)** Product Manager (PM-2) role — research-to-predict-features-before-friction
 - [ ] **[B-0155](backlog/P1/B-0155-github-settings-ruleset-split-git-native-preferred-aaron-2026-05-01.md)** GitHub settings refactor — split single ruleset into multiple smaller always-on rulesets, prefer git-native over legacy UI/CLI-only settings (Aaron 2026-05-01)
 - [ ] **[B-0156](backlog/P1/B-0156-typescript-standardization-non-install-scripts-aaron-2026-05-01.md)** TypeScript standardization — port every .sh outside install graph + every .py to TS (Aaron 2026-05-01)
+- [ ] **[B-0158](backlog/P1/B-0158-claude-rules-pattern-carved-sentences-only-aaron-2026-05-01.md)** Adopt `.claude/rules/<rule>.md` pattern + carved-sentences-only constraint (Aaron 2026-05-01)
 
 ## P2 — research-grade
 

docs/backlog/P1/B-0158-claude-rules-pattern-carved-sentences-only-aaron-2026-05-01.md

@@ -0,0 +1,206 @@
+---
+id: B-0158
+priority: P1
+status: open
+title: Adopt `.claude/rules/<rule>.md` pattern + carved-sentences-only constraint (Aaron 2026-05-01)
+created: 2026-05-01
+last_updated: 2026-05-01
+depends_on:
+  - B-0006
+  - B-0153
+# `depends_on` is a forward-compat schema field per
+# `memory/feedback_backlog_hygiene_cadenced_refactor_look_for_overlap_not_just_dump_2026_04_23.md`
+# 2026-05-01 extension; informational-only until tooling lands.
+---
+
+# B-0158 — Adopt `.claude/rules/<rule>.md` pattern + carved-sentences-only constraint
+
+## Outcomes solved
+
+This row is a **trajectory** (per the parallel-trajectories
+discipline in `docs/active-trajectory.md` +
+`memory/feedback_outcomes_over_vanity_metrics_goodhart_resistance.md`).
+Outcomes it serves, ordered:
+
+1. **Reduce always-on context-load** — CLAUDE.md is 23.7k
+   chars; GOVERNANCE.md is 40.4k chars (AT the proven 40k
+   ceiling — the sibling repo's incident report).
+   AGENTS.md is 19.2k. Total always-on across our four
+   surfaces: 107.5k chars. Sibling-repo experience
+   indicates measurable performance impact above 40k
+   per-file. Lazy-loading rule bodies into
+   `.claude/rules/<rule>.md` keeps CLAUDE.md terse
+   (headline + 1-paragraph summary + pointer per rule).
+
+2. **Reduce goldfish-ontology recurrence** — per
+   `memory/feedback_otto_buddy_spin_up_when_waiting_aaron_2026_05_01.md`,
+   Otto rebuilds existing rules within 30 min of
+   forgetting them. Per-rule canonical homes in
+   `.claude/rules/<rule>.md` make grep-before-author
+   trivially cheap (one file = one rule = one query).
+
+3. **Carved-sentences-only compression** — Aaron 2026-05-01:
+   *"you are only allowed carved statments in the rules
+   compression is key."* Forces every rule to be
+   blade-shaped, not prose-shaped. Composes with the
+   carved-sentences architectural-claim cluster (in-flight
+   integration) + CSAP framework. The constraint is the
+   discipline.
+
+4. **DORA-aligned — lower lead-time** — every session-wake
+   that reads CLAUDE.md pays the always-on tax. Reducing
+   that tax shortens the time-from-wake-to-productive-action
+   for every agent invocation.
+
+## External anchor
+
+Sibling repo `../no-copy-only-learning-agents-insight`
+ships this pattern at production scale:
+
+- `.claude/rules/agent-behavior.md` — 30k chars (the big one)
+- `.claude/rules/dst-and-dispose.md` — 12k chars
+- `.claude/rules/dependencies-and-citus.md` — 5k chars
+- `.claude/rules/claude-md-lean.md` — 4k chars (the
+  meta-rule documenting the split)
+- Smaller files (`backend.md`, `frontend.md`,
+  `development-workflow.md`) are **`@<path>` references**
+  delegating to existing `.cursor/rules/<rule>.mdc`
+  entries — parallel-harness consolidation.
+
+The sibling's `claude-md-lean.md` documents the proven
+incident: a fresh Claude Code session reported
+*"Large CLAUDE.md will impact performance (50.1k chars
+> 40.0k)"* after rules accreted directly into CLAUDE.md.
+The split was the mitigation. We are 23.7k on CLAUDE.md
+today + 40.4k on GOVERNANCE.md — the ceiling is on the
+horizon, not theoretical.
+
+## Aaron's framing — load-bearing constraints
+
+Aaron 2026-05-01 (verbatim):
+
+> *"i mean honestly the way
+> ../no-copy-only-learning-agents-insight does .claude/rules
+> seems like the way to go and you are only allowed carved
+> statments in the rules compression is key."*
+
+Two load-bearing constraints:
+
+1. **Adopt the sibling-repo `.claude/rules/<rule>.md`
+   pattern** — proven design, no new architecture
+   needed. Mechanical anchor: their pattern is the
+   reference.
+2. **Carved-sentences-only** — TIGHTER than the sibling
+   repo (whose rules carry full prose bodies). Our
+   constraint: every rule in `.claude/rules/<rule>.md`
+   is a *carved sentence* (blade-shaped statement, no
+   prose-explanation). Per the CSAP framework + the
+   carved-sentences architectural-claim cluster
+   (in-flight integration; the canonical filename will
+   resolve once that PR merges). Compression is the
+   discipline. (Aaron's verbatim "carved statments" maps
+   to the established factory term "carved sentences" —
+   single-source vocabulary per the engagement-under-
+   discipline memo's mirror-language convention.)
+
+The combination is novel: sibling's lazy-load shape +
+our carved-sentence constraint. The sibling's pattern
+proves the lazy-load works at scale; the carved-sentence
+constraint is our addition.
+
+## Phase 1 — design + first three rules (P1)
+
+**Acceptance criteria**:
+
+1. **`.claude/rules/<rule>.md` directory created** — empty
+   initially, with a `README.md` that defines:
+   - The carved-sentences-only constraint
+   - Pointer back to CSAP framework for rule promotion
+   - Pointer to `claude-md-lean.md` for the lazy-load
+     pattern
+2. **Three pilot rules migrated** — pick the three rules
+   currently in CLAUDE.md that are heaviest (longest
+   prose) AND most frequently violated:
+   - Candidate 1: verify-before-deferring
+   - Candidate 2: future-self-not-bound
+   - Candidate 3: substrate-or-it-didn't-happen (Otto-363)
+   Each becomes a `.claude/rules/<name>.md` with a
+   carved-sentence body + reference incident pointer.
+3. **CLAUDE.md updated** — replace the three rules' bodies
+   with: heading + 1-paragraph summary + pointer line.
+4. **Char-count verification** — `wc -c CLAUDE.md` after
+   migration shows reduction proportional to the moved
+   bodies.
+5. **Carved-sentences linter** — pre-commit hook that
+   verifies every `.claude/rules/<rule>.md` body is
+   ≤ N sentences (N to be determined; candidate: 3
+   carved-sentence claims max per rule). Linter is a
+   B-0153 lint-class candidate.
+
+## Phase 2 — bulk migration (P2)
+
+Migrate remaining standing rules from CLAUDE.md +
+GOVERNANCE.md into `.claude/rules/<rule>.md` files.
+Each migration:
+
+1. Identify the rule's full prose body in
+   CLAUDE.md/GOVERNANCE.md
+2. Carve it down to ≤ N carved sentences for
+   `.claude/rules/<rule>.md`
+3. Replace original prose with summary + pointer
+4. Verify char-count budget
+5. Update copilot-instructions.md if relevant
+
+GOVERNANCE.md at 40.4k is the priority surface
+(already at the proven ceiling).
+
+## Phase 3 — parallel-harness consolidation (P3)
+
+Mirror the sibling-repo's `@<path>` reference pattern
+for rules that have `.cursor/rules/<rule>.mdc`
+equivalents (per the agent-orchestra harness adapters
+trajectory, tasks #324-339). Each
+`.claude/rules/<rule>.md` can be a 1-line `@<path>`
+pointer to a Cursor-equivalent rule, or vice-versa,
+keeping both harnesses sync'd from a single canonical
+source.
+
+## Composes with
+
+- B-0006 — MEMORY.md compression pass (sibling
+  cleanup; both serve the broader compression
+  discipline)
+- B-0153 — pre-commit lint suite (Phase 1's
+  carved-sentences-linter is a candidate class)
+- `memory/feedback_otto_buddy_spin_up_when_waiting_aaron_2026_05_01.md`
+  — goldfish-ontology fix; lazy-loaded rules make
+  pre-author grep cheap
+- `memory/feedback_outcomes_over_vanity_metrics_goodhart_resistance.md`
+  — outcomes-driven framing
+- `memory/feedback_detect_changes_pattern_sibling_repo_parallel_optimized_external_anchor_aaron_2026_05_01.md`
+  — sibling-repo as external anchor (same anchor as
+  this row; different pattern surface)
+- The carved-sentences architectural-claim cluster
+  (PR #1111 in-flight; canonical memory filename
+  resolves once that PR lands) — the
+  CSAP framework that defines what "carved" means
+- `memory/feedback_prefer_mechanical_external_anchors_over_aaron_as_anchor_aaron_2026_05_01.md`
+  — sibling-repo IS the mechanical anchor, not
+  Aaron-as-anchor
+
+## What this row does NOT do
+
+- **NOT a license to immediately bulk-migrate every
+  rule** — Phase 1 ships three pilot rules; bulk
+  migration is Phase 2 + 3 with explicit cadence.
+- **NOT a replacement for `memory/`** — `.claude/rules/`
+  holds *standing rules* (BP-NN-class); `memory/` holds
+  *episodic substrate* (corrections, observations,
+  preferences). Different stores, different shapes.
+- **NOT a hard ceiling shift** — the 40k char ceiling is
+  Claude Code's reported threshold; if Anthropic raises
+  it, the priority shifts but the goldfish-reduction
+  outcome remains.
+- **NOT a green-field architecture** — the sibling-repo
+  pattern is the reference design; we adopt + add the
+  carved-sentence constraint, we don't invent.