fix(memory-ingest): pass --include-gitignored to gbrain import

gstack-artifacts-init writes an ignore-everything .gitignore (a bare `*`,
headed "Do not edit") at the root of ~/.gstack. The memory ingest stages
pages into ~/.gstack/.staging-ingest-<pid>-<ts>/, which is inside that
repo, and gbrain's markdown collector honours .gitignore. The collector
therefore matches every staged file against `*` and collects zero.

The failure is silent. gbrain import exits 0 having imported nothing while
the ingest prints `written: N` from the STAGED count rather than the
imported count, so a run that indexes nothing looks identical to a healthy
one and the memory corpus quietly stops growing.

Reproduction, using git's own ignore machinery (no gbrain needed):

  git init .
  mkdir -p .staging-ingest-12345/learnings
  echo x > .staging-ingest-12345/learnings/page.md
  printf '*\n' > .gitignore
  git ls-files --others --exclude-standard   # -> empty

Passing --include-gitignored makes the import independent of whatever
.gitignore sits above the staging directory. Adding a negation to the
generated .gitignore is the alternative, but that file is gstack-owned and
marked "Do not edit", so any regeneration silently reintroduces the bug.

Adds a regression pin in the shape of memory-ingest-no-put_page.test.ts,
plus a behavioural test for the collision itself. Both source pins fail
against the unpatched file.

bin/gstack-memory-ingest.ts

@@ -1417,7 +1417,20 @@ function runGbrainImport(
     // inside Next.js / Prisma / Rails projects with their own
     // .env.local (codex review #7 — defense in depth on top of the
     // parent gstack-gbrain-sync seeding the bun grandchild's env).
-    const child = spawnGbrainAsync(["import", stagingDir, "--no-embed", "--json"]);
+    // --include-gitignored is load-bearing, not a convenience. Pages are
+    // staged into ~/.gstack/.staging-ingest-<pid>-<ts>/, and ~/.gstack is a
+    // git repo whose .gitignore is `*`. `gbrain import` honours .gitignore,
+    // so without this flag it collects files=0 and imports NOTHING, while
+    // still reporting `written: N` from the staged count. Silent data loss
+    // on every run. A working run logs `import.collect_files done ... files=N`
+    // with N > 0 and takes minutes, not seconds.
+    const child = spawnGbrainAsync([
+      "import",
+      stagingDir,
+      "--no-embed",
+      "--include-gitignored",
+      "--json",
+    ]);
     _activeImportChild = child;
     let stdout = "";
     let stderr = "";