docs(provenance): migrate the corpus to the Research registry grammar

Repoint every `Research doc:` at the plugin's Research registry
(git/sources.md, pre-commit/sources.md, gitea/sources.md,
agentsmd/sources.md), keeping the old topic-doc link as a parenthetical
`(digest: ...)` annotation. Brace expansions and the gitea-releases
semicolon pair collapse to one path.

Entries with no registry (org-commit-conventions, org-git-conventions,
governance-secrets-hard-prohibition, adr-0002-0003-two-tier-claude-md)
now declare `none` plus `Basis:` bullets. The two git entries cite
core/instructions/git.md and commits.md as `(removed in 5deed07)`.

Remove the house-vale-3-15-2-repro entry and its source_keys citations
from vale-config and vale-run. It claimed six behaviours were reproduced
against purpose-built fixtures in this repo, but the entry was added in
d1afdbe with no test or fixture files, and none exists in history. The
behavioural rules stay; only the unbacked provenance claim goes.

Refs: #121
ADR: 0028
Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01EGHFJextYtVQseaHPDDhxB

plugins/git/.apm/skills/git-commits/references/sources.md

@@ -14,27 +14,29 @@ Sources extracted from the git plugin research phase. Only sources that directly
 ## conventional-commits-spec
 
 - **Description:** Conventional Commits Specification (v1.0.0) — message format, types, breaking changes, footer rules
-- **Research doc:** plugins/git/docs/research/docs/git/commits.md § "Conventional Commits Specification (v1.0.0)"
+- **Research doc:** plugins/git/docs/research/docs/git/sources.md (digest: plugins/git/docs/research/docs/git/commits.md § "Conventional Commits Specification (v1.0.0)")
 - **Contributing files:** SKILL.md, references/conventional-commits-spec.md, references/create-commit.md
 - **Status:** extracted
 
 ## commitlint-config-conventional
 
 - **Description:** commitlint config-conventional preset — validation constraints (max 100 chars header, no trailing periods, lowercase type, 11-type set enforcement)
-- **Research doc:** plugins/git/docs/research/docs/git/commits.md § "commitlint Constraints (`config-conventional`)"
+- **Research doc:** plugins/git/docs/research/docs/git/sources.md (digest: plugins/git/docs/research/docs/git/commits.md § "commitlint Constraints (`config-conventional`)")
 - **Contributing files:** SKILL.md, references/conventional-commits-spec.md, references/create-commit.md
 - **Status:** extracted
 
 ## org-commit-conventions
 
 - **Description:** Organization commit message body template and git conventions (atomic commits, no `--no-verify`, no force-push main/master, `rtk git` wrapper) — content fully embedded in this skill; the org's `core/instructions/git.md` and `core/instructions/commits.md` are provenance only and are not a live dependency
-- **Research doc:** core/instructions/commits.md, core/instructions/git.md (org convention, not part of the plugin's research corpus)
+- **Research doc:** none
+- **Basis:** core/instructions/commits.md (removed in 5deed07)
+- **Basis:** core/instructions/git.md (removed in 5deed07)
 - **Contributing files:** SKILL.md, references/commit-template.md, references/create-commit.md, references/rewrite-history.md
 - **Status:** extracted
 
 ## context7-git-htmldocs
 
 - **Description:** Official Git HTML documentation — `git commit --squash`/`--fixup`, `git rebase --autosquash`, and `git cherry-pick` range and abort semantics
-- **Research doc:** plugins/git/docs/research/docs/git/cli-reference.md § "Committing", § "Rebasing", § "Cherry-picking"
+- **Research doc:** plugins/git/docs/research/docs/git/sources.md (digest: plugins/git/docs/research/docs/git/cli-reference.md § "Committing", § "Rebasing", § "Cherry-picking")
 - **Contributing files:** SKILL.md, references/rewrite-history.md, references/cherry-pick.md
 - **Status:** extracted