Bust executor prompt cache on workspace SKILL.md layout changes

Add workspace_skills_layout_signature (hash of paths + mtimes + sizes) and fold it into get_executor_prompt_static and manager prebuild cache keys. Add tests for signature drift and cache invalidation.

Co-authored-by: Cursor <cursoragent@cursor.com>

runtime/prompt_prebuild.py

@@ -10,6 +10,7 @@ from oclaw.runtime.agent_context import build_role_system_context
 from oclaw.runtime.agents.specialists import discover_specialist_ids
 from oclaw.runtime.direct_loop import tool_wire_freeze_status, warm_tool_wire_cache
 from oclaw.runtime.skill_role_binding import SKILL_ROLE_BINDING_KEY
+from oclaw.runtime.skills import workspace_skills_layout_signature
 from oclaw.runtime.system_prompt import get_executor_prompt_static, warm_executor_prompt_cache
 from oclaw.runtime.tools.catalog import default_registry
 from oclaw.runtime.workspaces.experts import expert_workspace_signature_token, list_experts
@@ -84,6 +85,7 @@ def get_manager_prompt_prebuild(
         bool(memory_enabled),
         expert_workspace_signature_token(),
         _manager_settings_signature(store),
+        workspace_skills_layout_signature(),
     )
     with _MANAGER_PREBUILD_CACHE_LOCK:
         cached = _MANAGER_PREBUILD_CACHE.get(cache_key)

runtime/skills.py

@@ -1,5 +1,6 @@
 from __future__ import annotations
 
+import hashlib
 import json
 import os
 import re
@@ -170,6 +171,38 @@ def discover_public_workspace_skill_names(skills_root: str | Path | None = None)
     return out
 
 
+def workspace_skills_layout_signature(skills_root: str | Path | None = None) -> str:
+    """Short hex signature that changes when any ``SKILL.md`` under the skills root moves or changes on disk.
+
+    Used to bust executor/manager prompt caches after install/uninstall/edit of workspace skills without
+    touching SQLite settings.
+    """
+    base = Path(skills_root).resolve() if skills_root else default_skills_root()
+    if not base.exists() or not base.is_dir():
+        return "0"
+    h = hashlib.sha256()
+    h.update(str(base).encode("utf-8", errors="ignore"))
+    h.update(b"\n")
+    try:
+        for skill_md in sorted(base.rglob("SKILL.md"), key=lambda p: str(p).lower()):
+            if not skill_md.is_file():
+                continue
+            try:
+                st = skill_md.stat()
+                rel = skill_md.relative_to(base).as_posix().lower()
+                h.update(rel.encode("utf-8", errors="ignore"))
+                h.update(str(int(st.st_mtime_ns)).encode("ascii", errors="ignore"))
+                h.update(b":")
+                h.update(str(int(st.st_size)).encode("ascii", errors="ignore"))
+                h.update(b"\n")
+            except OSError:
+                h.update(str(skill_md.resolve()).encode("utf-8", errors="ignore"))
+                h.update(b"\n?")
+    except OSError:
+        return "0:err"
+    return h.hexdigest()[:24]
+
+
 def _tool_origin(tool: "ToolSpec") -> str:
     nm = str(getattr(tool, "name", "") or "")
     if nm.startswith("mcp__"):
@@ -344,6 +377,7 @@ __all__ = [
     "build_skill_registry",
     "default_skills_root",
     "discover_workspace_skill_manifests",
+    "workspace_skills_layout_signature",
     "load_skill_manifest",
     "materialize_skills_from_tool_specs",
     "skill_runtime_diagnostics",

runtime/system_prompt.py

@@ -9,6 +9,7 @@ from oclaw.platform.config.paths import PROJECT_ROOT
 from oclaw.runtime.memory_stage import render_memory_context_block
 from oclaw.runtime.project_context_prompt import build_project_context_block
 from oclaw.runtime.skill_role_binding import SKILL_ROLE_BINDING_KEY
+from oclaw.runtime.skills import workspace_skills_layout_signature
 from oclaw.runtime.skills_prompt import build_skills_catalog_block
 from oclaw.runtime.skills_workspace_lane import (
     fs_safe_workspace_lane_segment,
@@ -205,6 +206,7 @@ def get_executor_prompt_static(
         str(skill_binding_role or "").strip().lower(),
         expert_workspace_signature_token(),
         _executor_prompt_settings_signature(store),
+        workspace_skills_layout_signature(),
         bool(tools is not None),
         int(bool(excl)),
         str(lane_seg or ""),