v4.6.0 — Customize archive + --restore

--customize now scaffolds an archive of every section of the source SKILL.md so dropped/trimmed functionality stays recoverable. A new --restore <fork-id> command re-evaluates that archive against the project's current signals and surfaces (or splices back) any sections whose relevance has grown — e.g. a Vue section dropped from a React-only fork can be patched back when Vue is added to the project, without re-customizing from scratch.

Added

• --customize archive scaffold — every fork now also gets <fork>/_archive/SKILL.original.md (verbatim source) and <fork>/_archive/dropped.json (every section with its original content, the action taken at customize time, the stack/framework keywords it mentions, and a snapshot of the project signals in effect). Schema: customize-archive/1.0. Format is intentionally simple so power users and other tools can read it without the engine.
• --restore FORK_ID — re-scans the project for current signals, re-scores every archived section against them, and lists patch candidates (sections whose relevance has grown, or whose original stack is now in the project). Preview-only by default.
• --restore FORK_ID --apply — splices the patch candidates into the fork's SKILL.md under a dated ## Restored from archive banner. Engine produces the patch; the agent then integrates it into the proper place and removes the banner (same split as --customize).
• _extract_section_stack_signals / _STACK_KEYWORDS — internal helper + vocabulary that recognizes ~60 framework/language/infra keywords in section prose so the archive knows what stack each section was for. Aligned with the tag/language vocabulary _scan_project produces.

Changed

• Plugin version 4.5.0 → 4.6.0 in plugin.json, registry.py VERSION constant, and the Python tier's SKILL.md metadata. Lite tier and claude.ai edition are unchanged in this release.
• SKILL.md --customize section now documents the _archive/ scaffold and the --restore companion.
• references/commands.md authoring table updated to list --customize and --restore.

Notes

• Forks created before 4.6.0 have no _archive/; running --restore on them prints a friendly note suggesting a re-run of --customize to regenerate the archive. The behavior is non-destructive.
• The archive deliberately preserves all sections (not just the dropped ones) so future re-analysis has the original full context, but only sections originally marked drop-or-rewrite, rewrite-stack, or keep-trim are flagged restorable: true.