Remove Instructions/Feedback + lp_profiles; sync retry, purge, mobile fixes (v0.1.0:104)

Removals (net -570 lines):
- Delete the Instructions and Feedback (feature_requests) pages + backend.
- Retire lp_profiles + investor_type across server, ingest, and seeds; migration
  0008 drops both empty tables (a sanctioned one-off exception to
  never-hard-delete). 0001's lp_profiles ALTER is removed so a fresh DB doesn't
  break the migration chain (live DBs already applied it).

Fixes:
- Email sync: a transient timeout no longer terminally parks a mailbox; the
  scheduler retries 'retrying' each cycle and re-includes errored accounts on an
  hourly backoff, so stuck mailboxes self-heal.
- Mobile Contacts: page through the full directory (server caps 500/page) -- one
  fetch silently truncated at 720, hiding people from the list and from search.
- Mobile email review: clock icon to set a reminder inline; approval cards show
  date/time.

New:
- Admin-only purge of soft-deleted rows (Settings -> Admin; type-to-confirm,
  refuses any row still linked to live data).

Tests: 45/45 (adds test_sync_ready + test_purge_soft_deleted). Reviewer pass
applied (NULL reminders.contact_id on contact purge). Bumped to v0.1.0:104.

backend/ingest/chunking.py

@@ -4,7 +4,7 @@ Maps each CRM record type to one or more chunks per docs/EMBEDDINGS.md:
   * one chunk per communications row          (doc_type = the comm type)
   * one chunk per MATCHED email               (doc_type = email; body only when matched)
   * one chunk per fundraising_investors notes LINE (the outreach log; split per line)
-  * one chunk each for free-text fields: contacts.notes, lp_profiles.notes,
+  * one chunk each for free-text fields: contacts.notes,
     opportunities (description + next_step), organizations.description
 
 Each chunk carries a canonical `lp_id` (resolved via entity_links) and a `date_ts`
@@ -104,13 +104,6 @@ def build_chunks(conn):
         chunks.append(_mk(f"contacts.notes:{r['id']}", lp, lp_name, person,
                           "contact_note", to_epoch(r["updated_at"]), r["notes"], "contacts", r["id"]))
 
-    # lp_profiles.notes
-    for r in conn.execute("""SELECT lp.id, lp.contact_id, lp.notes, lp.updated_at
-                             FROM lp_profiles lp WHERE lp.notes IS NOT NULL AND lp.notes <> '' AND lp.deleted_at IS NULL"""):
-        lp, lp_name, person = _contact_lp(r["contact_id"], person_canon, org_canon, name, contact_org)
-        chunks.append(_mk(f"lp_profiles.notes:{r['id']}", lp, lp_name, person,
-                          "lp_note", to_epoch(r["updated_at"]), r["notes"], "lp_profiles", r["id"]))
-
     # opportunities (description + next_step)
     for r in conn.execute("""SELECT id, contact_id, name, description, next_step, updated_at
                              FROM opportunities WHERE deleted_at IS NULL"""):