docs(post-mortem): Apply session start checklists and edit tool warnings

From gui_decoupling_controller track post-mortem:

workflow.md:
- Add mandatory session start checklist (6 items)
- Add code style section with 1-space indentation enforcement
- Add native edit tool warning with MCP alternatives

AGENTS.md:
- Add critical native edit tool warning
- Document MCP tool alternatives for file editing

tier1-orchestrator.md:
- Add session start checklist

tier2-tech-lead.md:
- Add session start checklist
- Add tool restrictions section (allowed vs forbidden)
- Add explicit delegation pattern

tier3-worker.md:
- Add task start checklist

tier4-qa.md:
- Add analysis start checklist

conductor/workflow.md

@@ -1,5 +1,50 @@
 # Project Workflow
 
+## Session Start Checklist (MANDATORY)
+
+Before ANY other action in a new session:
+
+1. [ ] Read `conductor/workflow.md` (this file)
+2. [ ] Read `conductor/tech-stack.md`
+3. [ ] Read `conductor/product.md`
+4. [ ] Read relevant `docs/guide_*.md` for current task domain
+5. [ ] Check `TASKS.md` for active/in-progress tracks
+6. [ ] Announce: "Context loaded, proceeding to [task]"
+
+**BLOCK PROGRESS** until all checklist items are confirmed.
+
+## Code Style (MANDATORY - Python)
+
+- **1-space indentation** for ALL Python code (NO EXCEPTIONS)
+- **CRLF line endings** on Windows
+- Use `./scripts/ai_style_formatter.py` for formatting validation
+- **NO COMMENTS** unless explicitly requested
+- Type hints required for all public functions
+
+### CRITICAL: Native Edit Tool Destroys Indentation
+
+The native `Edit` tool DESTROYS 1-space indentation and converts to 4-space.
+
+**NEVER use native `edit` tool on Python files.**
+
+Instead, use Manual Slop MCP tools:
+- `manual-slop_py_update_definition` - Replace function/class
+- `manual-slop_set_file_slice` - Replace line range
+- `manual-slop_py_set_signature` - Replace signature only
+
+Or use Python subprocess with `newline=''` to preserve line endings:
+```python
+python -c "
+with open('file.py', 'r', encoding='utf-8', newline='') as f:
+    content = f.read()
+content = content.replace(old, new)
+with open('file.py', 'w', encoding='utf-8', newline='') as f:
+    f.write(content)
+"
+```
+
+## Guiding Principles
+
 ## Guiding Principles
 
 1. **The Plan is the Source of Truth:** All work must be tracked in `plan.md`