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/lint/.apm/skills/vale-config/references/configuration-reference.md

@@ -2,7 +2,6 @@
 topic: configuration-reference
 source_keys:
   - context7-websites-vale-sh
-  - house-vale-3-15-2-repro
 ---
 
 ## Core Settings
@@ -82,7 +81,7 @@ Only *package* styles need fetching. A style whose YAML rule files are already c
 - `Vale.Avoid` — enforces the project's rejected vocabulary terms.
 - `Vale.Repetition` — flags repeated words (e.g. "the the").
 
-`Packages` (top-level, what `vale sync` downloads) and `BasedOnStyles` (per-glob, what activates) are separate keys: a style lints a file only once it is in both. Every row below reproduced against Vale 3.15.2 (slug `house-vale-3-15-2-repro`):
+`Packages` (top-level, what `vale sync` downloads) and `BasedOnStyles` (per-glob, what activates) are separate keys: a style lints a file only once it is in both. Every row below reproduced against Vale 3.15.2:
 
 | Configuration | Result |
 |---|---|
@@ -98,7 +97,7 @@ Only *package* styles need fetching. A style whose YAML rule files are already c
 
 ## Frontmatter Scopes
 
-House-verified behaviour, not documented on vale.sh — reproduced locally against Vale 3.15.2 (slug `house-vale-3-15-2-repro`).
+House-verified behaviour, not documented on vale.sh — reproduced locally against Vale 3.15.2.
 
 A rule scoped to `text.frontmatter.<key>` (e.g. `text.frontmatter.description`) matches reliably when that field's value is a single physical line, and breaks on most — not all — multi-line forms. Multi-line forms spanning 2+ lines: