refactor: simplify workflow to user-selectable 6-command architecture

Simplifies the workflow orchestrator from hardcoded 11-step atomic operations
to user-selectable 6-command workflow with context passing.

Core changes:
- WorkflowStep enum: 11 steps → 6 commands (create-branch, planning, execute, commit, create-pr, prp-review)
- workflow_orchestrator.py: 367 lines → 200 lines with command stitching loop
- Remove workflow_type field, add selected_commands parameter
- Simplify agent names from 11 → 6 constants
- Remove test/review phase config flags (now optional commands)

Deletions:
- Remove test_workflow.py, review_workflow.py, workflow_phase_tracker.py
- Remove 32 old command files from .claude/commands
- Remove PRPs/specs and PRD files from version control
- Update .gitignore to exclude specs, features, and validation markdown files

Breaking changes:
- AgentWorkOrder no longer has workflow_type field
- CreateAgentWorkOrderRequest now uses selected_commands instead of workflow_type
- WorkflowStep enum values incompatible with old step history

56 files changed, 625 insertions(+), 15,007 deletions(-)

python/.claude/commands/agent-work-orders/start-server.md

@@ -0,0 +1,33 @@
+# Start Servers
+
+Start both the FastAPI backend and React frontend development servers with hot reload.
+
+## Run
+
+### Run in the background with bash tool
+
+- Ensure you are in the right PWD
+- Use the Bash tool to run the servers in the background so you can read the shell outputs
+- IMPORTANT: run `git ls-files` first so you know where directories are located before you start
+
+### Backend Server (FastAPI)
+
+- Navigate to backend: `cd app/backend`
+- Start server in background: `uv sync && uv run python run_api.py`
+- Wait 2-3 seconds for startup
+- Test health endpoint: `curl http://localhost:8000/health`
+- Test products endpoint: `curl http://localhost:8000/api/products`
+
+### Frontend Server (Bun + React)
+
+- Navigate to frontend: `cd ../app/frontend`
+- Start server in background: `bun install && bun dev`
+- Wait 2-3 seconds for startup
+- Frontend should be accessible at `http://localhost:3000`
+
+## Report
+
+- Confirm backend is running on `http://localhost:8000`
+- Confirm frontend is running on `http://localhost:3000`
+- Show the health check response from backend
+- Mention: "Backend logs will show structured JSON logging for all requests"