feat: refresh shared skills catalog

skills/check/SKILL.md

@@ -1,98 +1,21 @@
 ---
 name: check
 description: >
-  Read-only drift detector comparing SPEC.md against current codebase.
-  Audits invariants (§V), interface shapes (§I), and task completion (§T), reporting violations with file:line citations.
-  Use when asked to "check drift", "audit spec", "spec vs code", or before releasing.
-concerns: [system-one-balance]
+  Audit an existing SPEC.md against code when asked to check drift, audit the spec, or compare spec versus implementation.
+scope: global
 ---
 
-# Check — Drift Detector
+# Spec drift audit
 
-Pure diagnostic audit. Reports violations and interface drift. Strictly read-only; writes nothing.
+Read-only: inspect files and available evidence; do not edit, sync, or commit.
+If no `SPEC.md` exists, report that fact without creating one.
 
-Spec drifting silently from code is the primary failure mode of long-lived projects. `check` catches drift before it becomes production defects.
-
----
-
-## Phase 0: Setup and Protocols
-
-1. **Non-Negotiable Invariants**:
-   - **Zero Writes**: Never edit code or `SPEC.md`. Report findings only.
-   - Every violation must cite `file:line` evidence.
-   - If `SPEC.md` is absent at repo root, report "no spec found" and exit.
-
----
-
-## Phase 1: Ingest and Check
-
-1. Ingest `SPEC.md` from the project root.
-2. Parse audit scope from arguments:
-   - `§V`: Audit invariants only (default).
-   - `§I`: Audit external interfaces only.
-   - `§T`: Audit task status against reality.
-   - `--all` (or empty): Audit all three sections.
-
----
-
-## Phase 2: Processing (Core Logic)
-
-### Step 1: Audit Invariants (§V)
-For each `V<n>` invariant:
-1. Translate invariant into a verifiable assertion about code.
-2. Search and inspect corresponding files.
-3. Classify state:
-   - **HOLD**: Invariant actively satisfied with test or code assertion.
-   - **VIOLATE**: Invariant actively violated in implementation.
-   - **UNVERIFIABLE**: Invariant has no corresponding automated test or code guard.
-
-### Step 2: Audit Interfaces (§I)
-For each interface defined in §I:
-1. Locate implementation in routes, CLI, or exported functions.
-2. Classify state:
-   - **MATCH**: Code shape matches §I specification exactly.
-   - **DRIFT**: Implementation exists but signatures, parameters, or return types diverge.
-   - **MISSING**: Interface declared in spec but absent from code.
-   - **EXTRA**: Code exposes public endpoints/flags not documented in §I.
-
-### Step 3: Audit Tasks (§T)
-For each `T<n>` row:
-1. If status is `x`: verify claimed files/tests exist in git. If absent, flag **STALE**.
-2. If status is `~`: note as in-progress.
-3. If status is `.`: note as pending.
-
----
-
-## Phase 3: The System One Balance Pass
-
-- **Augment, Don't Handcuff**:
-  - Report findings concisely without lecturing or auto-triggering refactors.
-  - Provide actionable remedy hints for each class of drift, leaving decisions to the user.
-
----
-
-## Phase 4: Output Execution & Verification
-
-Emit the structured Caveman drift report:
-
-```markdown
-## Drift Report
-
-### §V Invariants
-- V2 VIOLATE: src/auth/mw.ts:47 uses `<` instead of `≤`.
-- V5 UNVERIFIABLE: no test covers concurrent refund boundary.
-
-### §I Interfaces
-- I.api DRIFT: POST /v1/charge returns `{result}` instead of `{id}`. routes/charge.py:82.
-- I.cmd MISSING: `limiter bench` absent from CLI definitions.
-
-### §T Tasks
-- T3 STALE: marked `x` but auth middleware file not found in tree.
-
-### Summary
-- X violations, Y drifts, Z missing, W stale.
-- **Remedy Hints**:
-  - VIOLATE / DRIFT: Invoke `spec` with `bug: <V.n>` or fix code at cited lines.
-  - MISSING: Invoke `build §T.n` or `spec amend §T`.
-  - STALE: Invoke `spec amend §T` to reset status.
-```
+1. Read the requested sections; default to §V, §I, and §T.
+2. For invariants, distinguish supported behavior, demonstrated violations, and
+   missing evidence. A test's presence alone does not prove an invariant holds.
+3. Compare public interfaces with implementations and callers; identify missing,
+   extra, or changed contracts with file/line evidence.
+4. Check task completion against the promised behavior, rather than only whether
+   named files exist. Report incomplete or stale statuses.
+5. Give concise findings, evidence, and useful remedies. Do not launch refactors,
+   impose release gates, or run test commands that would violate read-only scope.