feat: add route-aware pricing estimates (#1695)

Salvaged from PR #1563 by @kshitijk4poor. Cherry-picked with authorship preserved.

- Route-aware pricing architecture replacing static MODEL_PRICING + heuristics
- Canonical usage normalization (Anthropic/OpenAI/Codex API shapes)
- Cache-aware billing (separate cache_read/cache_write rates)
- Cost status tracking (estimated/included/unknown/actual)
- OpenRouter live pricing via models API
- Schema migration v4→v5 with billing metadata columns
- Removed speculative forward-looking entries
- Removed cost display from CLI status bar
- Threaded OpenRouter metadata pre-warm

Co-authored-by: kshitij <82637225+kshitijk4poor@users.noreply.github.com>

tests/test_hermes_state.py

@@ -657,7 +657,7 @@ class TestSchemaInit:
     def test_schema_version(self, db):
         cursor = db._conn.execute("SELECT version FROM schema_version")
         version = cursor.fetchone()[0]
-        assert version == 4
+        assert version == 5
 
     def test_title_column_exists(self, db):
         """Verify the title column was created in the sessions table."""
@@ -713,12 +713,12 @@ class TestSchemaInit:
         conn.commit()
         conn.close()
 
-        # Open with SessionDB — should migrate to v4
+        # Open with SessionDB — should migrate to v5
         migrated_db = SessionDB(db_path=db_path)
 
         # Verify migration
         cursor = migrated_db._conn.execute("SELECT version FROM schema_version")
-        assert cursor.fetchone()[0] == 4
+        assert cursor.fetchone()[0] == 5
 
         # Verify title column exists and is NULL for existing sessions
         session = migrated_db.get_session("existing")