feat: autonomous setup flow and per-feature doc reconciliation

- setup-project: run end-to-end without pausing for human approval between steps
- add-feature Step 8: reconcile all six persistent docs with each implemented feature
- AGENTS.md: align document-management principles with the new sync rule
- opencode.json: simplify permission config

opencode.json

@@ -1,20 +1,7 @@
 {
   "$schema": "https://opencode.ai/config.json",
-  "instructions": ["AGENTS.md"],
-  "permission": {
-    "skill": "allow",
-    "bash": {
-      "*": "ask",
-      "npm *": "allow",
-      "npx *": "allow",
-      "node *": "allow",
-      "git *": "allow",
-      "ls": "allow",
-      "ls *": "allow",
-      "cat *": "allow",
-      "mkdir *": "allow",
-      "date": "allow",
-      "date *": "allow"
-    }
-  }
-}
+  "instructions": [
+    "AGENTS.md"
+  ],
+  "permission": "allow"
+}