feat: export guidelines - the guideline pages as a generated GUIDELINES.md, pushed into the captured repositories behind the Guideline Push Gate (#179)

Files changed:
- AGENTS.md
- CHANGES.md
- README.md
- VERSION
- docs/why-gates-are-code.md
- instructions/gates.md
- instructions/kb-profiles.md
- kb/CONTRACT.md
- kb/CONVENTIONS.md
- kb/CONVENTIONS.md.template
- raw/CONTRACT.md
- tools/CONTRACT.md
- tools/README.md
- tools/chemenu/cli.py
- tools/chemenu/cli_contract.py
- tools/chemenu/commands/export_cmd.py
- tools/chemenu/commands/page_ops.py
- tools/chemenu/commands/raw_cmd.py
- tools/chemenu/commands/search.py
- tools/chemenu/guideline_export.py
- tools/chemenu/kb_scan.py
- tools/chemenu/repo_capture.py
- tools/chemenu/search/filters.py
- tools/chemenu/tests/test_cli.py
- tools/chemenu/tests/test_export_guidelines.py

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01SnAJ7Z3CpVD3PRbN73QtU2

README.md

@@ -227,6 +227,18 @@ tell the LLM `Update the captured repositories`, and it checks them, takes one c
 run into the wiki and says how many are still behind. Git uses your own keys and credential
 helpers - nothing is stored in the repository.
 
+The same repositories can get something back: the wiki's guidelines, as one generated
+`GUIDELINES.md` in their root. Which pages count as guidelines is your decision, written down in
+`kb/CONVENTIONS.md` (§ Guidelines for other repositories); `tools/wikitool export guidelines
+--tag guideline` prints the file as it would be written. A repository takes part by carrying a
+`GUIDELINES.md` whose first line is `<!-- wikitool:export kind=guidelines -->` - commit that one
+line there, and point the repository's own `AGENTS.md` at the file (Claude Code:
+`@GUIDELINES.md`). A hand-written `GUIDELINES.md` is never touched. Then tell the LLM
+`Roll out the guidelines to the captured repositories`: it runs `export guidelines --push`, which
+stops before pushing anything (the **Guideline Push Gate**) and shows you, per repository, what
+would change - the LLM puts every diff in front of you, and only your approval pushes one commit
+per repository, changing only that file, straight onto its branch.
+
 ### Querying Knowledge
 
 Ask questions naturally:
@@ -407,6 +419,11 @@ this" code, not an error - printing the full file list and the
 `--confirm <token>` line that publishes it. The token digests that file list,
 so a clearance never carries to a changeset the user did not see.
 
+**Guideline push.** `tools/wikitool export guidelines --push` exits **42** the same way (the
+**Guideline Push Gate**) before it writes `GUIDELINES.md` into any captured repository, printing
+every target's status and diff and the `--confirm <token>` line. The token digests each target's
+branch tip and the file, so a moved branch or an edited guideline asks again.
+
 **Iteration/cost limits.** Every `tools/wikitool` call is checked against a
 hard, code-enforced per-session budget before it runs (default: 60 calls, or
 3 identical calls in a row) - not just a prompt instruction to stop. Past the