chore(template): clean-slate template snapshot from bb4a0c7

Curated, product-agnostic snapshot of the post-story-04 tree: demo
content deleted, auth-only reference feature, web-next shell, all gates
green. Product-specific docs, ADRs 027-029, PRDs/epics/archive, editor
library traces, and product naming are curated out; generic template
repairs (coverage provider devDeps, root test:coverage script, live
lint fixes, root-only release-please) are kept. See TEMPLATE.md for
provenance, curation list, and usage.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_016j8z4VHjedXDTjEDNg7qHK

packages/core-eslint/rules/_manifest-source.js

@@ -0,0 +1,38 @@
+import path from "node:path";
+import { parseManifestFully } from "./_manifest-ast.js";
+
+/**
+ * Reads a feature.manifest.ts and returns { name, requiredCores }.
+ * Backed by the AST parser from _manifest-ast.js — no longer uses regex.
+ *
+ * Returns: { name: string, requiredCores: string[] } | null
+ */
+export function readManifestSource(manifestPath) {
+  const full = parseManifestFully(manifestPath);
+  if (!full) return null;
+  return { name: full.name, requiredCores: full.requiredCores };
+}
+
+/**
+ * Canonical manifest path for a given feature package root.
+ */
+export function manifestPathForFeature(featureRoot) {
+  return path.join(featureRoot, "src", "feature.manifest.ts");
+}
+
+/**
+ * Given an absolute file path and the monorepo root, returns the feature
+ * package root that contains the file (e.g. /repo/packages/auth). Returns
+ * null when the file lives outside the packages/ tree.
+ *
+ * Assumes the conventional layout `packages/<feature>/src/...`.
+ */
+export function featureRootForFile(filepath, repoRoot) {
+  const packagesDir = path.join(repoRoot, "packages");
+  if (!filepath.startsWith(packagesDir + path.sep)) return null;
+  const rel = filepath.slice(packagesDir.length + 1); // e.g. "auth/src/..."
+  const slash = rel.indexOf(path.sep);
+  if (slash === -1) return null;
+  const featureName = rel.slice(0, slash);
+  return path.join(packagesDir, featureName);
+}