optimize(seo): add resources/depth-matrix.md (depth/weights/dedup/envelope) + reference from SKILL.md (d6 target)

skills/seo/SKILL.md

@@ -39,6 +39,15 @@ This skill orchestrates TWO specialist agents running in parallel, then
 merges their output into a single `.claude/audits/SEO.md` report. It is the main
 entry point for any SEO/GEO work on a web project.
 
+## Resources
+
+- `resources/depth-matrix.md` — depth-decision rules (LOCAL vs FULL),
+  score-weight table per axis, dedup rules with sibling skills (/validate,
+  /harden), and the envelope schema for `.claude/audits/SEO.md`.
+
+Read `resources/depth-matrix.md` at the start of STEP 0 — it pre-answers
+several questions and keeps token cost down by removing repeated explanations.
+
 ## STEP 0 — Collect shared context (ONCE)
 
 Before spawning any agent, collect the context both agents need.

skills/seo/resources/depth-matrix.md

@@ -0,0 +1,57 @@
+# SEO + GEO depth-decision matrix
+
+Use this table during STEP 0 when the user has not already specified depth.
+
+| Signal in `$ARGUMENTS` or environment | Depth | Why |
+|---|---|---|
+| `local`, `code-only`, `quick`, `rapide`, `pre-deploy` | LOCAL | No live URL needed; fast feedback in CI or local dev. |
+| `full`, `complet`, `externe`, `live`, `production`, includes `https://...` URL | FULL | Live verification + Core Web Vitals + AI visibility require external calls. |
+| Local-business signals (NAP detected: phone, address, opening hours, GMB) | FULL recommended (warn if LOCAL chosen) | NAP audit requires reading the live site + cross-checking directories. |
+| User asks "ranking", "GMB", "fiche Google", "Knowledge Panel" | FULL | These are live-only signals. |
+| Repository has `<lang>.html`/`hreflang` but no production URL provided | LOCAL with note | Cannot validate hreflang resolution without live URL — flag as user action. |
+| `--no-external` flag set | LOCAL forced | Honour explicit override even if FULL signals present. |
+
+# Score-weight table (out of /20)
+
+| Axis | LOCAL weight | FULL weight |
+|---|---|---|
+| Meta + canonical + lang | 3 | 3 |
+| JSON-LD / Schema.org | 3 | 3 |
+| Sitemap + robots.txt + llms.txt | 3 | 3 |
+| Headings + alt + i18n | 3 | 3 |
+| Core Web Vitals | 0 | 3 |
+| Security + redirects + indexability | 4 | 2 |
+| External presence (GMB, citations, Wikidata) | 0 | 3 |
+| Content shape (TL;DR, definition lead, citable stats) | 4 | 0 |
+
+LOCAL caps at 20. FULL caps at 20. Never report above 20.
+
+# Dedup rules — overlap with sibling skills
+
+| Finding type | Owner skill | If reported by /seo, what to do |
+|---|---|---|
+| HTML validity errors (W3C nu validator) | /validate | Drop from /seo report; note `"see /validate report for HTML validity"`. |
+| WCAG accessibility | /validate | Drop. |
+| Missing CSP / HSTS / 404 page / HTTP→HTTPS | /harden | Drop unless it directly affects indexability (then mention with cross-link). |
+| Wikidata / sameAs / Knowledge Panel | /seo (GEO) | Owned here. |
+| llms.txt | /seo (GEO) | Owned here. |
+
+# Envelope schema for `.claude/audits/SEO.md`
+
+```
+# SEO + GEO Audit — <date>
+DEPTH: LOCAL | FULL
+SITE: <root path or production URL>
+SCORE_CLASSICAL: <n>/20
+SCORE_GEO: <n>/20
+
+## §1 Critical alerts
+## §2 Score breakdown
+## §3 Classical SEO findings (meta, sitemap, JSON-LD, headings, …)
+## §4 Local SEO / NAP (only if local-business)
+## §5 Core Web Vitals (FULL only)
+## §6 Security + indexability cross-refs (link to /harden)
+## §7 GEO / AI optimisation
+## §8 Fix bundle (auto-applied in aggressive mode)
+## §9 User actions (manual)
+```