fix: journey routing tests — CLAUDE.md routing rules + stronger descriptions

Three journey E2E tests (ideation, ship, debug) were failing because
Claude answered directly instead of invoking the Skill tool. Root cause:
skill descriptions in system-reminder are too weak to override Claude's
default behavior for tasks it can handle natively.

Fix has two parts:
1. CLAUDE.md routing rules in test workdir — Claude weighs project-level
   instructions higher than skill description metadata
2. "Proactively invoke" (not "suggest") in office-hours, investigate,
   ship descriptions — reinforces the routing signal

10/10 journey tests now pass (was 7/10).

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

investigate/SKILL.md

@@ -7,8 +7,9 @@ description: |
   analyze, hypothesize, implement. Iron Law: no fixes without root cause.
   Use when asked to "debug this", "fix this bug", "why is this broken",
   "investigate this error", or "root cause analysis".
-  Proactively suggest when the user reports errors, unexpected behavior, or
-  is troubleshooting why something stopped working.
+  Proactively invoke this skill (do NOT debug directly) when the user reports
+  errors, 500 errors, stack traces, unexpected behavior, "it was working
+  yesterday", or is troubleshooting why something stopped working.
 allowed-tools:
   - Bash
   - Read

investigate/SKILL.md.tmpl

@@ -7,8 +7,9 @@ description: |
   analyze, hypothesize, implement. Iron Law: no fixes without root cause.
   Use when asked to "debug this", "fix this bug", "why is this broken",
   "investigate this error", or "root cause analysis".
-  Proactively suggest when the user reports errors, unexpected behavior, or
-  is troubleshooting why something stopped working.
+  Proactively invoke this skill (do NOT debug directly) when the user reports
+  errors, 500 errors, stack traces, unexpected behavior, "it was working
+  yesterday", or is troubleshooting why something stopped working.
 allowed-tools:
   - Bash
   - Read