Merge pull request 'The catalogue prepares its own schema instead of migrating at start' (#130) from feat/the-catalogue-prepares-its-own-schema into main

It brought its schema up inside its runtime, on every start. That made a schema it could not reach a
crash loop rather than a stop, with the module graph keeping a gap and nothing saying so — which is
how a whole morning's builds went unrecorded. The mesh now prepares this module's state before it
starts this version and does not start it if that failed (novox/hq ADR 0135): the work moves to an
entrypoint the image names in MESH_PREPARE, beside the entrypoints it already names.

The reason it was at start — that a step blocking the apply would block the very apply bringing the
overlay up — stopped being true when a step's failure became its module's business rather than the
machine's (ADR 0136).

modules/gitea/client.ts

@@ -229,6 +229,17 @@ export class GiteaClient {
     return GiteaClient.mapPull(await this.request<any>(`/repos/${owner}/${repo}/pulls/${index}`));
   }
 
+  /** The files a merged pull request changed, as paths from the repository's root.
+   *
+   *  `limit` is what is asked for, and a merge that changed more says so rather than being read
+   *  page by page: what the mesh does with a partial list is treat the whole repository as changed,
+   *  so more pages would buy nothing. */
+  async listPullFiles(owner: string, repo: string, index: number, limit = 100): Promise<{ paths: string[]; truncated: boolean }> {
+    const files = await this.request<any[]>(`/repos/${owner}/${repo}/pulls/${index}/files?limit=${limit}`);
+    const paths = (files ?? []).map((f) => String(f?.filename ?? "")).filter((p) => p !== "");
+    return { paths, truncated: paths.length >= limit };
+  }
+
   async createPullRequest(
     owner: string,
     repo: string,

modules/gitea/index.ts

@@ -61,9 +61,17 @@ import { join } from "node:path";
 const mergedRecord = process.env.MESH_GITEA_STATE_DIR ? join(process.env.MESH_GITEA_STATE_DIR, "merged-announced.json") : null;
 const announced = new Set<string>();
 let primedMerges = false;
+// since is the moment the watching began: a merge made before it is history, whatever page of the
+// forge's listing it surfaces on. Without it, an old merge past the first page — pushed into view
+// as newer pull requests were updated — was announced as if it had just happened, and the mesh
+// rebuilt everything built from that repository, once per old merge (2026-09-28).
+let since = "";
 if (mergedRecord && existsSync(mergedRecord)) {
   try {
-    for (const sha of JSON.parse(readFileSync(mergedRecord, "utf8")) as string[]) announced.add(sha);
+    const kept = JSON.parse(readFileSync(mergedRecord, "utf8")) as string[] | { announced: string[]; since: string };
+    const list = Array.isArray(kept) ? kept : kept.announced;
+    for (const sha of list) announced.add(sha);
+    since = Array.isArray(kept) ? new Date().toISOString() : kept.since;
     primedMerges = true;
   } catch {
     // An unreadable record is treated as no record: prime again rather than re-announce history.
@@ -73,7 +81,7 @@ function keepAnnounced(): void {
   if (!mergedRecord) return;
   mkdirSync(join(mergedRecord, ".."), { recursive: true });
   const tmp = mergedRecord + ".tmp";
-  writeFileSync(tmp, JSON.stringify([...announced].slice(-2000)));
+  writeFileSync(tmp, JSON.stringify({ announced: [...announced].slice(-2000), since }));
   renameSync(tmp, mergedRecord);
 }
 async function pollMerged(client: GiteaClient): Promise<void> {
@@ -83,7 +91,14 @@ async function pollMerged(client: GiteaClient): Promise<void> {
     const pulls = await client.listPullRequests(repo.owner, repo.name, { state: "closed", sort: "recentupdate", limit: "20" });
     for (const pull of pulls) {
       if (!pull.merged || !pull.merge_commit_sha || announced.has(pull.merge_commit_sha)) continue;
-      if (primedMerges) {
+      // Announced only if merged since the watching began; recorded either way, so it is looked
+      // at once.
+      const fresh = !!pull.merged_at && !!since && pull.merged_at > since;
+      if (primedMerges && fresh) {
+        // What it changed, asked for only now: a module is rebuilt because a file inside its own
+        // directory moved, and without this every module built from a repository is rebuilt for a
+        // change to any of them (novox/hq 04-ISSUES/131).
+        const changed = await client.listPullFiles(repo.owner, repo.name, pull.number);
         await emit("pull.merged", {
           owner: repo.owner,
           repo: repo.name,
@@ -95,12 +110,18 @@ async function pollMerged(client: GiteaClient): Promise<void> {
           merged_at: pull.merged_at,
           clone_url: repo.clone_url,
           html_url: pull.html_url,
+          paths: changed.paths,
+          paths_truncated: changed.truncated,
         });
+        // Said, because a trigger that fires silently is indistinguishable from one that did not
+        // fire (novox/hq 04-ISSUES/131) — this line is how an operator knows the mesh was told.
+        console.log(`[gitea] announced merge ${repo.full_name}#${pull.number} (${pull.merge_commit_sha.slice(0, 8)}) into ${pull.base}`);
       }
       announced.add(pull.merge_commit_sha);
       changed = true;
     }
   }
+  if (!primedMerges) since = new Date().toISOString();
   if (!primedMerges || changed) keepAnnounced();
   primedMerges = true;
 }

modules/gitea/tools/index.ts

@@ -233,6 +233,9 @@ export function getGiteaTools(gitea: GiteaClient): ToolDefinition[] {
         await gitea.mergePullRequest(owner, repo, number, method, deleteBranch);
         // Read it again: the merge commit only exists now, and it is what a build is made from.
         const merged = await gitea.getPullRequest(owner, repo, number);
+        // And what it changed, so the mesh rebuilds the modules whose own files moved rather than
+        // every module built from the repository (novox/hq 04-ISSUES/131).
+        const changed = await gitea.listPullFiles(owner, repo, number);
         await emit("pull.merged", {
           owner,
           repo,
@@ -244,6 +247,8 @@ export function getGiteaTools(gitea: GiteaClient): ToolDefinition[] {
           merged_at: merged.merged_at,
           method,
           html_url: pull.html_url,
+          paths: changed.paths,
+          paths_truncated: changed.truncated,
         });
         return { merged: true, number, method, deleted_branch: deleteBranch };
       },

modules/mesh-catalog/Dockerfile

@@ -22,7 +22,7 @@ COPY . .
 # The compiler is invoked by its real path rather than through node_modules/.bin, whose entries are
 # symlinks to a launcher that requires its library relatively — resolved away when the base image
 # was assembled.
-RUN node /app/node_modules/typescript/bin/tsc pg.d.ts store.ts index.ts tools/index.ts \
+RUN node /app/node_modules/typescript/bin/tsc pg.d.ts store.ts index.ts tools/index.ts prepare/index.ts \
       --module NodeNext --moduleResolution NodeNext --target ES2022 --outDir dist
 
 # **A module may need something the base image does not carry.** The base holds what every module
@@ -48,3 +48,8 @@ COPY --from=build /deps/node_modules /app/modules/mesh-catalog/node_modules
 # to listen for what the builder announces. Serve binds the broker first, then imports these, so
 # `on()` has something to subscribe to.
 ENV MESH_TOOL_MODULES=/app/modules/mesh-catalog/dist/index.js,/app/modules/mesh-catalog/dist/tools/index.js
+
+# And what prepares this module's state, for the runtime's `prepare` mode (novox/hq ADR 0135). Named
+# here, beside the entrypoints above, because the module knows which of its files prepares its state
+# and nothing else could: the mesh asks one word and this says what answers it.
+ENV MESH_PREPARE=/app/modules/mesh-catalog/dist/prepare/index.js

modules/mesh-catalog/index.ts

@@ -14,10 +14,12 @@ import { Graph, type Made } from "./store.js";
 
 const graph = Graph.fromEnv();
 
-// Before subscribing, and idempotent. The runtime is restarted until its store is reachable, which
-// is the same arrangement model-usage uses: a schema step that had to reach the provider over the
-// overlay would block the very apply that brings the overlay up.
-await graph.migrate();
+// The schema is not brought up here. The mesh prepares this module's state before it starts this
+// version, and does not start it if that failed (novox/hq ADR 0135) — see prepare/index.ts. Doing it
+// at start made a schema that could not be reached a crash loop instead of a stop, with the graph
+// keeping a gap and nothing saying so. The reason it used to be here — that a step blocking the apply
+// would block the very apply that brings the overlay up — stopped being true when a step's failure
+// became this module's business and not the machine's (ADR 0136).
 
 /** What the builder says when it has built something. */
 interface Built {

modules/mesh-catalog/module.json

@@ -34,8 +34,10 @@
   "emits": [
     "registered",
     "upgraded",
-    "rebuild-needed"
+    "rebuild-needed",
+    "catching-up"
   ],
+  "prepares": true,
   "resources": [
     {
       "id": "mesh-state",

modules/mesh-catalog/prepare/index.ts

@@ -0,0 +1,17 @@
+// The catalogue's state, brought to the shape this version needs (novox/hq ADR 0135).
+//
+// **The mesh runs this before the version that needs it, and does not start that version if it
+// fails** — and the refusal reaches this module and nothing else on the machine
+// (novox/hq ADR 0136). That is the whole difference from where this used to happen: at start, inside
+// the runtime, a schema that could not be brought up was a crash loop, the graph kept a gap, and
+// nothing anywhere said so.
+//
+// Nothing here connects to the broker. Preparation runs before the version that would use it, so
+// there is nothing yet to talk to; the runtime's `prepare` mode imports this and awaits it, and this
+// process exiting non-zero is how the host knows not to start the runtime.
+import { Graph } from "../store.js";
+
+const graph = Graph.fromEnv();
+await graph.migrate();
+console.log("[mesh-catalog] the module graph's schema is what this version needs");
+await graph.close();

modules/mesh-catalog/tsconfig.json

@@ -12,6 +12,7 @@
     "pg.d.ts",
     "store.ts",
     "index.ts",
-    "tools/index.ts"
+    "tools/index.ts",
+    "prepare/index.ts"
   ]
 }