feat(skills): import Spec-Driven Development (SDD) suite

- Add grill: calibrated plan stress-testing before speccing
- Add spec: sole mutator of SPEC.md with format specification
- Add caveman: token-compression dialect for invariants and tasks
- Add review: adversarial pre-implementation refutation of spec
- Add build: single-threaded plan-to-execute loop with external oracles
- Add check: read-only drift detector comparing code vs invariants
- Add backprop: bug-to-spec feedback loop binding regression tests
- Add deepen: complexity reduction and interface shrinking pass
- Format all skills to 5-phase Skill Architect anatomy with System One balance
- Synchronize symlinks across OpenCode, Codex, and Claude Code

skills/spec/references/format.md

@@ -0,0 +1,79 @@
+# SPEC.md Canonical Format Specification
+
+`SPEC.md` is the single source of truth for Spec-Driven Development (SDD). All sections are written in Caveman encoding.
+
+---
+
+## 1. Document Sections
+
+### §G — Goal
+One single line in Caveman dialect stating the product intent.
+```markdown
+# §G
+build distributed rate limiter with sliding-window Redis Lua script.
+```
+
+### §C — Constraints
+Hard constraints, technology stack limits, and explicit out-of-scope declarations.
+```markdown
+# §C
+- Go 1.22+ stdlib + go-redis/v9.
+- ⊥ external dependencies outside Redis.
+- memory overhead ≤ 50MB @ 100k keys.
+- out of scope: clustering, dynamic cluster topology changes.
+```
+
+### §I — Interfaces
+Public membranes: CLI commands, API endpoints, environment variables, or exported signatures.
+```markdown
+# §I
+api: POST /v1/limiter/check → 200 {allowed:bool, remaining:int, reset_ms:int}
+cmd: `limiter-cli bench --rate=<n>` → stdout benchmark summary
+env: REDIS_URL ! set
+```
+
+### §R — Research Log (Optional)
+Distilled external facts, primary documentation links, or RFC references.
+```markdown
+# §R
+id|domain|finding|source
+R1|redis lua|reclaim memory via `redis.replicate_commands()`|redis.io/docs/manual/programmability/lua-api
+R2|token bucket|GCRA algorithm reduces atomic roundtrips to 1|en.wikipedia.org/wiki/Generic_cell_rate_algorithm
+```
+
+### §V — Invariants
+Non-negotiable behavioral invariants. Numbered monotonically `V1`, `V2`, ...
+```markdown
+# §V
+V1: ∀ check req → atomic sliding window evaluate in Redis Lua
+V2: Redis down → fail open (return allowed:true with header warning)
+V3: latency p99 ≤ 2ms @ 10k rps
+```
+
+### §T — Tasks
+Ordered pipe table of implementation tasks. Numbered `T1`, `T2`, ...
+- Status: `.` todo, `~` wip, `x` done.
+- `cites`: Invariants (`V<n>`) or Interfaces (`I.<name>`) that the task must satisfy.
+```markdown
+# §T
+id|status|task|cites
+T1|x|scaffold Redis client with fallback|V2,I.api
+T2|~|implement sliding window Lua script|V1
+T3|.|expose HTTP endpoint & healthcheck|I.api
+```
+
+### §B — Bug Log
+Feedback memory capturing bugs and regressions found during build/check/production.
+```markdown
+# §B
+id|date|cause|fix
+B1|2026-04-20|lua script script error on empty redis key|V1
+```
+
+---
+
+## 2. Sectioned Ownership
+- `spec` is the sole mutator of `SPEC.md`.
+- `build` flips only task status (`.` → `~` → `x`).
+- `check` is strictly read-only.
+- `backprop` appends `§B` rows and drafts `§V` lines.