feat: refresh shared skills catalog

skills/spec/references/format.md

@@ -1,13 +1,13 @@
 # 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.
+`SPEC.md` is the single source of truth for Spec-Driven Development (SDD). Use concise plain English or the project's adopted compact notation.
 
 ---
 
 ## 1. Document Sections
 
 ### §G — Goal
-One single line in Caveman dialect stating the product intent.
+A concise statement of product intent.
 ```markdown
 # §G
 build distributed rate limiter with sliding-window Redis Lua script.
@@ -37,8 +37,8 @@ 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
+R1|dependency version|verified version-specific constraint|<primary-source-url>
+R2|transaction behavior|verified atomicity guarantee|<primary-source-url>
 ```
 
 ### §V — Invariants
@@ -73,7 +73,8 @@ B1|2026-04-20|lua script script error on empty redis key|V1
 ---
 
 ## 2. Sectioned Ownership
-- `spec` is the sole mutator of `SPEC.md`.
+- `spec` owns goals, constraints, interfaces, research, task definitions, and general invariants.
 - `build` flips only task status (`.` → `~` → `x`).
 - `check` is strictly read-only.
-- `backprop` appends `§B` rows and drafts `§V` lines.
+- `backprop` appends `§B` rows and amends bug-related `§V` invariants.
+- Each owner may edit its sections within the authorized task without a separate handoff.