dream.py: raise_for_status on manifest writes; total_chunks as actual corpus count

Two correctness bugs in dream_pipeline manifest assembly.

write_manifest at lines 487-491 swallowed HTTP 4xx/5xx responses
silently. requests.put() only raises on transport-level errors (DNS,
connection refused, timeout); 401/403/500/507 come back as Response
objects and never trigger the except. The code printed "Manifest
written" while the manifest never persisted. The same file's deliver()
function at line 434 already used response.raise_for_status() — the
pattern was already established, write_manifest just skipped it.

Fix: bind the response and call raise_for_status() before the success
print. The except message changes from "(non-critical)" to "manifest
not persisted" because HTTP failure now means manifest data was lost,
which is critical, not quiet.

corpus_data["total_chunks"] at lines 621-622 stored
delta["new_chunks"], duplicating the sibling field
new_chunks_since_last_dream. The field name claimed absolute corpus
size; the value was a delta of recently-touched files. Verified in
live manifests: total_chunks: 0 while pgvector held 11,379+ document
embeddings.

Fix: query SELECT COUNT(*) FROM embeddings inside dream_pipeline,
store as total_chunks. Tightly-scoped one-shot connect via the
existing get_pg() helper. Telemetry query failure is treated as
non-critical and falls back to 0 — pgvector hiccup should not crash
an otherwise successful dream pipeline.

Bonus finding (not fixed in this commit): new_chunks_since_last_dream
is itself misnamed. observe_corpus() reads the watcher's mtime cache
and counts files (not chunks) whose mtime is newer than last_dream.
Both fields were "files touched since last dream" duplicated under
two different names; this commit fixes only the total_chunks
semantics. Renaming new_chunks_since_last_dream is out of scope —
manifests are write-only telemetry today, no consumer reads either
field, and the rename is a separate decision.

Verification: real pipeline run produced manifest with total_chunks
matching SELECT COUNT(*) directly; doubled as a smoke test for the
embedder cache (single Loading weights line), type_distribution
propagation, and the manifest write success path.

scripts/dream.py

@@ -485,10 +485,11 @@ def write_manifest(date_str, stage_data, corpus_data):
     auth = (NEXTCLOUD_USER, NEXTCLOUD_PASSWORD)
     url = f"{DREAMS_WEBDAV}/dream-manifest-{date_str}.json"
     try:
-        requests.put(url, data=content.encode("utf-8"), auth=auth, timeout=30)
+        response = requests.put(url, data=content.encode("utf-8"), auth=auth, timeout=30)
+        response.raise_for_status()
         print(f"Manifest written: Journal/Dreams/dream-manifest-{date_str}.json")
     except Exception as e:
-        print(f"Manifest write failed (non-critical): {e}")
+        print(f"Manifest write failed — manifest not persisted: {e}")
 
 
 def dream_pipeline(type_filter=None):
@@ -618,8 +619,20 @@ def dream_pipeline(type_filter=None):
     # Write manifest
     all_session_sources = list(session_retrieved)
     all_session_folders = list({extract_folder(s) for s in all_session_sources})
+    total_chunks = 0
+    pg = None
+    try:
+        pg = get_pg()
+        cur = pg.cursor()
+        cur.execute("SELECT COUNT(*) FROM embeddings")
+        total_chunks = cur.fetchone()[0]
+    except Exception as e:
+        print(f"total_chunks query failed (non-critical): {e}")
+    finally:
+        if pg is not None:
+            pg.close()
     corpus_data = {
-        "total_chunks": delta.get("new_chunks", 0),
+        "total_chunks": total_chunks,
         "new_chunks_since_last_dream": delta.get("new_chunks", 0),
         "days_since_last_dream": round(delta.get("days_since_dream", 0), 2),
         "substrate": "pgvector",