diff --git a/.github/pull_request_template.md b/.github/pull_request_template.md
new file mode 100644
index 0000000000..305f8393d7
--- /dev/null
+++ b/.github/pull_request_template.md
@@ -0,0 +1,49 @@
+<!--
+PR template for Zuhn. Codex reviews PRs against this scaffold and the
+project's CLAUDE.md / AGENTS.md conventions.
+
+Pure data updates (insights, principles, sources, views) flow through
+post-ingest's auto-git step directly to main and do NOT use PRs.
+This template is for code, schema, hooks, briefs, or docs.
+-->
+
+## What this changes
+
+<!-- 1-3 sentences naming the user-facing or behavior-facing change. -->
+
+## Why
+
+<!-- The problem being solved or the capability being added. -->
+
+## Scope
+
+- [ ] Code (scripts, schemas, agents, hooks)
+- [ ] CI / GitHub workflows
+- [ ] Tests
+- [ ] Briefs / docs / README
+- [ ] Skills
+- [ ] Other: ____
+
+## Risk surface
+
+<!-- What could break if this is wrong? Which parts of the pipeline
+     does this touch? Add nothing if risk is low; add specifics if not. -->
+
+## Tests
+
+<!-- New tests added, or rationale for not adding any. Reference test
+     files by path. -->
+
+## Out of scope
+
+<!-- Adjacent things you noticed but did not fix here. Helps reviewers
+     calibrate scope and prevents scope-creep ratchet. -->
+
+## Verification
+
+<!-- How you confirmed this works. Commands run, manual checks, etc. -->
+
+---
+
+🤖 If Codex review surfaces non-trivial findings, address or explicitly
+acknowledge each one before merging.
diff --git a/scripts/post-ingest.ts b/scripts/post-ingest.ts
index 3165c8e441..5c94f32bfc 100644
--- a/scripts/post-ingest.ts
+++ b/scripts/post-ingest.ts
@@ -32,6 +32,24 @@ async function appendToActivityLog(entry: string): Promise<void> {
   await writeFile(ACTIVITY_LOG, existing + line + "\n", "utf-8");
 }
 
+/**
+ * Classify a staged path as data (auto-committable to main) or not.
+ *
+ * Option B architecture: pure data updates flow through post-ingest's
+ * auto-git step directly to main. Anything else — scripts, configs,
+ * briefs, docs, schemas, hooks, GitHub workflows — must go through a
+ * branch + PR + Codex review. The guard in the auto-git step uses
+ * this predicate to refuse commits that mix code into a data run.
+ *
+ * Data scope is anything under `knowledge-base/`. The MASTER_INDEX,
+ * views, _summary files, and meta/ all live there.
+ */
+function isDataPath(path: string): boolean {
+  // Normalize POSIX-style separators (git output) regardless of host
+  const normalized = path.replace(/\\/g, "/");
+  return normalized.startsWith("knowledge-base/");
+}
+
 function buildAutoCommitMessage(): string {
   try {
     const diffStat = execFileSync(
@@ -207,32 +225,70 @@ async function main(): Promise<void> {
   let gitStatus = "SKIPPED";
   console.log("\n>> Auto-git");
   try {
-    // Stage knowledge-base/
+    // Stage knowledge-base/ — auto-git is intentionally narrow-scoped
+    // to data only. Code, briefs, and config changes go through PRs
+    // and are reviewed by the chatgpt-codex-connector GitHub App,
+    // which triggers automatically on pull_request events. No workflow
+    // file is needed; the App listens via webhooks.
     execFileSync("git", ["add", "knowledge-base/"], {
       stdio: "pipe",
       cwd: PROJECT_ROOT,
     });
 
-    // Check if there are staged changes
-    try {
-      execFileSync("git", ["diff", "--cached", "--quiet"], {
-        stdio: "pipe",
-        cwd: PROJECT_ROOT,
-      });
-      // Exit 0 means no changes
-      console.log("   No changes to commit.");
-      gitStatus = "NO_CHANGES";
-    } catch {
-      // Exit non-zero means there ARE staged changes — commit them
-      // Build a descriptive commit message from what actually changed
-      const commitMsg = buildAutoCommitMessage();
-      execFileSync(
-        "git",
-        ["commit", "-m", commitMsg],
-        { stdio: "pipe", cwd: PROJECT_ROOT }
+    // Guard: if any non-data file is staged (because the user staged
+    // it manually before running post-ingest), abort the auto-commit
+    // rather than mixing code into a data commit. This preserves the
+    // Option B invariant that auto-commits to main are data-only.
+    // Use -z for null-terminated output. Without it, git C-quotes
+    // non-ASCII filenames (default core.quotePath=true), turning paths
+    // like `knowledge-base/foo-ñ.md` into `"knowledge-base/foo-\303\261.md"`.
+    // The leading quote would defeat isDataPath's prefix check and
+    // misclassify legitimate Unicode-named data files as non-data,
+    // aborting auto-git on pure data runs.
+    const stagedFiles = execFileSync(
+      "git",
+      ["diff", "--cached", "--name-only", "-z"],
+      { encoding: "utf-8", cwd: PROJECT_ROOT },
+    )
+      .split("\0")
+      .filter(Boolean);
+
+    const nonDataFiles = stagedFiles.filter((f) => !isDataPath(f));
+
+    if (nonDataFiles.length > 0) {
+      console.error(
+        "   Auto-git aborted: non-data files are staged. Auto-commits must be data-only.",
+      );
+      console.error("   Staged non-data files:");
+      for (const f of nonDataFiles) console.error(`     - ${f}`);
+      console.error(
+        "   Resolve by either unstaging these (`git restore --staged <file>`) or",
+      );
+      console.error(
+        "   committing them manually on a feature branch + PR (Option B).",
       );
-      console.log(`   Committed: ${commitMsg}`);
-      gitStatus = "COMMITTED";
+      gitStatus = "ABORTED_NON_DATA_STAGED";
+    } else {
+      // Check if there are staged changes
+      try {
+        execFileSync("git", ["diff", "--cached", "--quiet"], {
+          stdio: "pipe",
+          cwd: PROJECT_ROOT,
+        });
+        // Exit 0 means no changes
+        console.log("   No changes to commit.");
+        gitStatus = "NO_CHANGES";
+      } catch {
+        // Exit non-zero means there ARE staged changes — commit them.
+        // Build a descriptive commit message from what actually changed.
+        const commitMsg = buildAutoCommitMessage();
+        execFileSync("git", ["commit", "-m", commitMsg], {
+          stdio: "pipe",
+          cwd: PROJECT_ROOT,
+        });
+        console.log(`   Committed: ${commitMsg}`);
+        gitStatus = "COMMITTED";
+      }
     }
   } catch (err: unknown) {
     const msg = err instanceof Error ? err.message : String(err);