fix(agent): deduplicate instruction loading and gate writes

.github/AGENT_MEMORY.md

@@ -13,12 +13,15 @@ Z-Shell uses GitHub-native records as the shared memory between humans and LLM a
 
 ## Agent Workflow
 
+External writes require explicit authorization. Without it, report the proposed issue, comment, or tracker update instead of performing it.
+
 Before starting non-trivial work:
 
 1. Search the owning repository for open issues and pull requests related to the task.
 2. Check linked tracker items and previous handoff comments.
 3. Prefer the most recent GitHub-visible state over local notes or LLM memory.
-4. If no issue exists for planned or deferred work, create one in the owning repository.
+4. If no issue exists for planned or deferred work, propose one. Create it only
+   when explicit external-write authority is present.
 
 While working:
 

AGENTS.md

@@ -13,6 +13,8 @@ This file is intentionally short. It complements, not replaces:
 
 Before non-trivial work, inspect `.github/instruction-surfaces.json`. This applies to every supported runtime. Match the current task categories and repository-relative file patterns against each manifest surface. When a surface declares both task and path dimensions, both dimensions must match before selecting it. Read every matched required surface before acting. If a runtime does not auto-load scoped guidance, open each matched required surface explicitly. Repeat this selection whenever the task, path, or repository scope changes.
 
+Treat byte-exact instruction content already present in the active instruction context as loaded. Manifest ownership entries and repository links do not request a second read. Re-evaluate only when the task, path, repository scope, or content changes.
+
 ## Agent-file placement
 
 Organization repository roots use `AGENTS.md` and permitted `.github/*` instruction surfaces. They must not contain root `CLAUDE.md` or `GEMINI.md`.
@@ -83,7 +85,10 @@ When working in z-shell repositories, optimize for:
 3. Check linked tracker items and previous handoff comments.
 4. Read the relevant ADRs, patterns, and runbooks.
 5. For cross-repo questions, search the organization before assuming the local repo is unique.
-6. If no issue exists for non-trivial planned work, create one in the owning repository.
+6. If no issue exists for non-trivial planned work, propose one. Create it only
+   when explicit external-write authority is present.
+
+Creating or updating issues, comments, pull requests, or tracker records requires explicit external-write authority. Without that authority, report the proposed external write instead.
 
 ## While editing
 
@@ -155,7 +160,9 @@ cannot own this mandatory rule.
 
 ## When this file is wrong
 
-Do not silently work around drift. Open or update an issue in `z-shell/.github`, explain what is wrong, and link the contradicting repository state.
+Do not silently work around drift. Propose an issue in `z-shell/.github` that
+explains what is wrong and links the contradicting repository state. Open or
+update it only when explicit external-write authority is present.
 
 ## See also
 

scripts/test_validate_agent_policy.py

@@ -1703,6 +1703,43 @@ def test_public_repository_requires_manifest_routing_for_all_runtimes(self) -> N
         for fragment in required_fragments:
             self.assertIn(fragment, policy)
 
+    def test_public_repository_deduplicates_loaded_content_and_gates_external_writes(
+        self,
+    ) -> None:
+        policy = (PUBLIC_ROOT / "AGENTS.md").read_text()
+        memory = (PUBLIC_ROOT / ".github/AGENT_MEMORY.md").read_text()
+
+        policy_fragments = (
+            "Treat byte-exact instruction content already present in the active "
+            "instruction context as loaded.",
+            "Manifest ownership entries and repository links do not request a "
+            "second read.",
+            "Creating or updating issues, comments, pull requests, or tracker "
+            "records requires explicit external-write authority.",
+            "Without that authority, report the proposed external write instead.",
+            "If no issue exists for non-trivial planned work, propose one.",
+        )
+        for fragment in policy_fragments:
+            self.assertIn(fragment, policy)
+
+        memory_fragments = (
+            "External writes require explicit authorization.",
+            "Without it, report the proposed issue, comment, or tracker update "
+            "instead of performing it.",
+            "If no issue exists for planned or deferred work, propose one.",
+        )
+        for fragment in memory_fragments:
+            self.assertIn(fragment, memory)
+
+        self.assertNotIn(
+            "If no issue exists for non-trivial planned work, create one",
+            policy,
+        )
+        self.assertNotIn(
+            "If no issue exists for planned or deferred work, create one",
+            memory,
+        )
+
     def test_public_repository_declares_learning_capture_surfaces(self) -> None:
         manifest = json.loads(
             (PUBLIC_ROOT / ".github/instruction-surfaces.json").read_text()