fix(hooks): remove all venv auto-repair code that deleted .venv directories

BREAKING: Removes automatic venv management that was causing session failures

Changes:
- Delete scripts/venv-repair.sh (was deleting and recreating venvs)
- Remove auto-repair code from projman/hooks/startup-check.sh
- Remove venv-repair call from scripts/post-update.sh
- Remove rm -rf .venv instructions from docs/UPDATING.md and CONFIGURATION.md
- Update docs/CANONICAL-PATHS.md to remove venv-repair.sh reference

Additionally:
- Add Pre-Change Protocol to CLAUDE.md (mandatory dependency check before edits)
- Add Pre-Change Protocol enforcement to claude-config-maintainer plugin
- Add Development Context section to CLAUDE.md clarifying which plugins are
  used in this project vs only being developed
- Reorganize commands table to separate relevant vs non-relevant commands

The venv auto-repair was the root cause of repeated MCP server failures,
requiring manual setup.sh runs after every session start.

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

plugins/claude-config-maintainer/agents/maintainer.md

@@ -277,6 +277,39 @@ Every CLAUDE.md should have:
 1. **Project Overview** - What is this?
 2. **Quick Start** - How do I build/test/run?
 3. **Important Rules** - What must I NOT do?
+4. **Pre-Change Protocol** - Mandatory dependency check before code changes
+
+### Pre-Change Protocol Section (MANDATORY)
+
+**This section is REQUIRED in every CLAUDE.md.** It ensures Claude performs comprehensive dependency analysis before making any code changes.
+
+```markdown
+## ⛔ MANDATORY: Before Any Code Change
+
+**Claude MUST show this checklist BEFORE editing any file:**
+
+### 1. Impact Search Results
+Run and show output of:
+```bash
+grep -rn "PATTERN" --include="*.sh" --include="*.md" --include="*.json" --include="*.py" | grep -v ".git"
+```
+
+### 2. Files That Will Be Affected
+Numbered list of every file to be modified, with the specific change for each.
+
+### 3. Files Searched But Not Changed (and why)
+Proof that related files were checked and determined unchanged.
+
+### 4. Documentation That References This
+List of docs that mention this feature/script/function.
+
+**User verifies this list before Claude proceeds. If Claude skips this, stop immediately.**
+
+### After Changes
+Run the same grep and show results proving no references remain unaddressed.
+```
+
+**When analyzing a CLAUDE.md, flag as HIGH priority issue if this section is missing.**
 
 ### Optional Sections (as needed)