docs(bugs): mark BUG-03 and BUG-05 FIXED (e2f2314) + update PLAN Phase 26

BUGS.md: BUG-03 and BUG-05 status -> FIXED with commit ref and fix summary.
PLAN.md: Phase 26 items 3 and 5 marked FIXED; add progress note.

BUGS.md

@@ -67,7 +67,12 @@ the authoritative, issue-by-issue record lives **here**.
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 ### BUG-03 — DTC/MIL codes are never persisted; lost on OBD disconnect or reboot
-- **Status**: `OPEN`
+
+- **Status**: `FIXED` (commit `e2f2314`; pending deploy/verify → CLOSED)
+- **Fix**: Persist MIL + codes to SQLite on each poll (`save_dtc_state`), `/api/dtc` falls back to
+  the persisted snapshot when OBD is offline, `get_overview_stats` counts the real `dtc` table,
+  and a schema migration rebuilds the unused `NAME/STATUS/DTC_ID` table. Cleared codes are tracked
+  via `IS_SET` + `FIRST_SEEN_AT`/`LAST_SEEN_AT`. Tests: `tests/test_dtc_persistence.py`.
 - **Severity**: Medium (lost diagnostic data; also a stats bug)
 - **Area**: `modules/app_obd.py`, `modules/app_sql.py`, `get_overview_stats`
 - **Phase**: Phase 26
@@ -101,7 +106,6 @@ the authoritative, issue-by-issue record lives **here**.
   two systems agree. Note this may re-split/recompute existing server trips — get owner sign-off
   before recomputing, and re-run `scripts/recompute_trips.py` after the fix.
 - **Acceptance**: A real drive with a parked gap produces the same number of trips on the server
-  as on the Pi.
 
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