Define skill lifecycle and add lifecycle markers to bundled skills

[Delqhi]

Goal

Establish a canonical lifecycle for SIN-Code ecosystem skills so users and agents know whether a bundled skill is native, external, or deprecated.

Proposed Lifecycle

• Phase 1 — External MCP Skill: functionality lives in a separate Python MCP repo (e.g. OpenSIN-Code/SIN-Code-*-Skill).
• Phase 2 — Bundled SKILL.md: a local, offline-ready documentation copy is embedded in SIN-Code/skills/.
• Phase 3 — Go-native sin-code <skill> subcommand: the functionality is implemented directly in the SIN-Code binary.
• Phase 4 — Deprecated / Archived: the external repo is marked deprecated and eventually archived once the native implementation is stable.

Tasks

• Add lifecycle frontmatter key to every bundled SKILL.md with values: native, external, deprecated.
• Update scripts/validate_skill.py to require/validate lifecycle in bundled skills.
• Extend mcpclient/registry.go and skillmgr.KnownSkills() to carry a status/lifecycle field.
• Update sin-code skills list to print lifecycle/status markers (e.g. [native], [external], [deprecated]).
• Document the lifecycle in AGENTS.md or docs/SKILLS.md.

Initial Mapping

Skill	Lifecycle	Canonical Source
goal-mode	native	sin-code goal
websearch	deprecated	web_search_bundle (Go-native)
grill-me	external	SIN-Code-Grill-Me-Skill
scheduler	external	SIN-Code-Scheduler-Skill
marketplace	external	SIN-Code-Marketplace-Skill
codocs	external	SIN-Code-Codocs-Skill
doc-coauthoring	external	SIN-Code-Doc-Coauthoring-Skill
context-bridge	external	SIN-Code-Context-Bridge-Skill
honcho / honcho-rollback	external	SIN-Code-Honcho-Rollback-Skill
frontend-design	external	SIN-Code-Frontend-Design-Skill
mcp-server-builder	external	SIN-Code-MCP-Server-Builder-Skill
browser-tools	external	SIN-Browser-Tools
cj-dropshipping	external	cj-dropshipping-skill + SIN-Shop-Center/SIN-CJDropshipping-Bundle
stripe	external	SIN-Shop-Center/SIN-Stripe-Bundle
tiktok-shop	external	SIN-Shop-Center/SIN-eCommerce-Scraper-Bundle

Acceptance Criteria

• python3 scripts/validate_skill.py --all-bundled --strict passes for all skills including lifecycle.
• sin-code skills list shows lifecycle markers.
• mcpclient/registry.go and skillmgr.KnownSkills() agree on status.

[Delqhi]

Closed: shipped in PR #218 (feat(skills): lifecycle markers, issue #139). All 34 bundled SKILL.md files now carry a lifecycle: native|external|deprecated field with canonical: source-of-truth. scripts/sync_lifecycle.py and scripts/lifecycle_map.yaml are the maintenance workflow; sin-code skill list prints the markers; validate_skill.py --strict enforces.