grounding: wire matched email bodies into the LP-feedback corpus

_ground_feedback_corpus now pulls matched email bodies (the richest objection
signal) alongside communications and grid notes, round-robin merged so email is
never crowded out by a flat LIMIT, per-item capped at 4000 chars to keep the local
minimize tractable on long threads, and degrading gracefully when the email tables
are absent. Email remains Tier-2-sensitive: it only ever enters the redaction
boundary, never Claude directly. Inert until Gmail capture is enrolled. Not yet
deployed (bundles into the next release with the meeting-notes work).
Test: test_ground_corpus.py.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

backend/server.py

@@ -3788,17 +3788,36 @@ class CRMHandler(BaseHTTPRequestHandler):
         return self.send_json({"data": res})
 
     def _ground_feedback_corpus(self, conn, limit=60):
-        """Raw LP-feedback prose for grounding (communications + grid notes). Sensitive
-        Tier-2-heavy text; ONLY ever passed into the redaction boundary, never to Claude
-        directly."""
-        items = []
-        for q in ("SELECT body FROM communications WHERE body IS NOT NULL AND TRIM(body)<>'' ORDER BY communication_date DESC LIMIT ?",
-                  "SELECT notes FROM fundraising_investors WHERE notes IS NOT NULL AND TRIM(notes)<>'' LIMIT ?"):
+        """Raw LP-feedback prose for grounding, newest-first, balanced across sources:
+        matched email bodies (the richest objection signal), logged communications, and
+        fundraising grid notes. Sensitive Tier-2-heavy text; ONLY ever passed into the
+        redaction boundary, never to Claude directly."""
+        # Email bodies are capped per item (long threads/quote-chains) to keep the local
+        # minimize tractable; only `matched` emails (tied to a known investor/contact) are
+        # pulled. Sources are round-robin merged so email is always represented even when
+        # communications/notes are plentiful, rather than crowded out by a flat LIMIT.
+        sources = (
+            "SELECT SUBSTR(body_text,1,4000) FROM emails WHERE match_status='matched' "
+            "AND body_text IS NOT NULL AND TRIM(body_text)<>'' ORDER BY sent_at DESC LIMIT ?",
+            "SELECT body FROM communications WHERE body IS NOT NULL AND TRIM(body)<>'' "
+            "ORDER BY communication_date DESC LIMIT ?",
+            "SELECT notes FROM fundraising_investors WHERE notes IS NOT NULL AND TRIM(notes)<>'' LIMIT ?",
+        )
+        buckets = []
+        for q in sources:
             try:
-                items += [r[0] for r in conn.execute(q, (limit,))]
+                buckets.append([r[0] for r in conn.execute(q, (limit,))])
             except Exception:
-                pass
-        return items[:limit]
+                buckets.append([])   # table absent (e.g. email integration not migrated) -> skip
+        items, i = [], 0
+        while len(items) < limit and any(i < len(b) for b in buckets):
+            for b in buckets:
+                if i < len(b):
+                    items.append(b[i])
+                    if len(items) >= limit:
+                        break
+            i += 1
+        return items
 
     def handle_architect_ground(self, user, body):
         """Ground an objection register in real LP feedback THROUGH the redaction boundary