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

instructions/gates.md

@@ -74,7 +74,7 @@ Not a gate you may widen: the prefix list is a constant in the tool. `--path <di
 scopes a large change into reviewable batches, which is a legitimate alternative to one big
 clearance.
 
-Background: [[Mass-Update Gate]] (`kb/concepts/Mass-Update Gate.md`).
+Background: the [[Mass-Update Gate]] concept page in `kb/`.
 
 ### Publish-Remote Gate
 
@@ -215,7 +215,7 @@ never in response to a gate refusal.** The plan is the human approval the gate w
 have to ask for; a refusal means that approval has not been given yet. If you are tempted to
 re-export the variable after an `ERROR` line, that is the gate working.
 
-Background: [[Iteration and Cost Limits]] (`kb/concepts/Iteration and Cost Limits.md`).
+Background: the [[Iteration and Cost Limits]] concept page in `kb/`.
 
 ## Scope