Add worktree config and comprehensive roadmap with user stories

.pi/worktree.json

@@ -0,0 +1,15 @@
+{
+  "dir": ".worktrees",
+  "branchPrefix": "feature/",
+  "linkEnvFiles": true,
+  "postCreate": [
+    "python3 -m venv .venv 2>/dev/null || true",
+    ".venv/bin/pip install -r requirements.txt -r requirements-dev.txt 2>/dev/null || pip install -r requirements.txt -r requirements-dev.txt",
+    "cp .env.example .env.local 2>/dev/null || true",
+    "echo 'Worktree $(basename $PWD) ready. Use docker compose up -d to start Redis.'"
+  ],
+  "preRemove": [
+    "docker compose down -v 2>/dev/null || true",
+    "rm -rf .venv"
+  ]
+}