fix(code-review): protect review artifact directories

plugins/compound-engineering/skills/ce-code-review/SKILL.md

@@ -438,8 +438,11 @@ Generate a unique run identifier before dispatching any agents. This ID scopes a
 ```bash
 RUN_ID=$(date +%Y%m%d-%H%M%S)-$(head -c4 /dev/urandom | od -An -tx1 | tr -d ' ')
 mkdir -p "/tmp/compound-engineering/ce-code-review/$RUN_ID"
+chmod 700 "/tmp/compound-engineering/ce-code-review/$RUN_ID"
 ```
 
+mkdir honors the caller's umask, and this run directory contains per-reviewer findings and evidence, so owner-only permissions are required.
+
 Pass `{run_id}` to every persona sub-agent so they can write their full analysis to `/tmp/compound-engineering/ce-code-review/{run_id}/{reviewer_name}.json`.
 
 **Report-only mode:** Skip run-id generation and directory creation. Do not pass `{run_id}` to agents. Agents return compact JSON only with no file write, consistent with report-only's no-write contract.

plugins/compound-engineering/skills/ce-code-review/references/subagent-template.md

@@ -133,7 +133,7 @@ Rules:
 - Suppress any finding you cannot honestly anchor at `50` or higher (the actionable floor is `50`; anchors `0` and `25` are suppressed by synthesis anyway, so emitting them only adds noise). If your persona's domain description sets a stricter floor (e.g., anchor `75` minimum), honor it.
 - Every finding in the full artifact file MUST include at least one evidence item grounded in the actual code. The compact return omits evidence -- the evidence requirement applies to the disk artifact only.
 - Set `pre_existing` to true ONLY for issues in unchanged code that are unrelated to this diff. If the diff makes the issue newly relevant, it is NOT pre-existing.
-- You are operationally read-only. The one permitted exception is writing your full analysis to the `.context/` artifact path when a run ID is provided. You may also use non-mutating inspection commands, including read-oriented `git` / `gh` commands, to gather evidence. Do not edit project files, change branches, commit, push, create PRs, or otherwise mutate the checkout or repository state.
+- You are operationally read-only. The one permitted exception is writing your full analysis to the OS temp artifact path `/tmp/compound-engineering/ce-code-review/{run_id}/{reviewer_name}.json` when a run ID is provided. You may also use non-mutating inspection commands, including read-oriented `git` / `gh` commands, to gather evidence. Do not edit project files, change branches, commit, push, create PRs, or otherwise mutate the checkout or repository state.
 - Set `autofix_class` accurately. The classification governs whether the fixer applies the change automatically (`safe_auto`) or surfaces it for explicit review (`gated_auto` / `manual` / `advisory`). **The wrong-side cost is symmetric:** classifying a contract-change as `safe_auto` produces an unwanted edit; classifying a mechanical fix as `gated_auto` makes the user manually triage findings the fixer could have applied. Bias toward `safe_auto` when the rubric permits it. Use this decision guide:
   - `safe_auto`: The fix is local and deterministic — the fixer can apply it mechanically. **The test:** you can articulate the fix in one sentence with no "depends on" clauses, AND applying it doesn't change any of {function signature, public-API/response contract, error contract, security posture, permission model}. Examples: extracting a duplicated helper, adding a missing nil/null guard inside an internal function, fixing an off-by-one when the parallel pattern is in scope, adding a missing test for an existing public method, removing dead code, removing an unused import.
 

tests/review-skill-contract.test.ts

@@ -609,6 +609,30 @@ describe("ce-code-review contract", () => {
     }
   })
 
+  test("protects code-review artifact directories with owner-only permissions", async () => {
+    const content = await readRepoFile("plugins/compound-engineering/skills/ce-code-review/SKILL.md")
+
+    expect(content).toContain('mkdir -p "/tmp/compound-engineering/ce-code-review/$RUN_ID"')
+    expect(content).toContain('chmod 700 "/tmp/compound-engineering/ce-code-review/$RUN_ID"')
+    expect(content).toContain("mkdir honors the caller's umask")
+    expect(content).toContain("per-reviewer findings and evidence")
+    expect(content).toContain("owner-only permissions")
+  })
+
+  test("subagent template documents OS-temp artifact path", async () => {
+    const template = await readRepoFile(
+      "plugins/compound-engineering/skills/ce-code-review/references/subagent-template.md",
+    )
+
+    expect(template).toContain(
+      "/tmp/compound-engineering/ce-code-review/{run_id}/{reviewer_name}.json",
+    )
+    expect(template).toContain(
+      "The one permitted exception is writing your full analysis to the OS temp artifact path",
+    )
+    expect(template).not.toContain("`.context/` artifact path")
+  })
+
   test("leaves data-migration-expert as the unstructured review format", async () => {
     const content = await readRepoFile(
       "plugins/compound-engineering/agents/ce-data-migration-expert.agent.md",