fix: kb page references by title, not by moved path; Iteration and Cost Limits cites existing sections (#147 follow-up)

gates.md named kb/concepts/<Title>.md for two pages that live under
kb/concepts/workflows/; run_budget.py carried the same stale path. The
concept page pointed at AGENTS.md sections that do not exist, the same
defect #147 fixed in the refusal messages.

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

Files changed:
- CHANGES.md
- VERSION
- instructions/gates.md
- kb/concepts/INDEX.md
- kb/concepts/workflows/Iteration and Cost Limits.md
- kb/index.md
- kb/log.md
- tools/chemenu/commands/run_budget.py

kb/index.md

@@ -19,7 +19,7 @@ The page tables live in a generated `INDEX.md` inside each collection, linked be
 - **Entities:** 72
 - **Gtd:** 0
 - **Sources:** 29
-- **Last Updated:** 2026-09-19
+- **Last Updated:** 2026-09-26
 
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