[AZ-528] Consolidate c1_vio strategy facade orchestration spine

Replace 3-way byte-equivalent orchestration-spine duplication across
okvis2.py / vins_mono.py / klt_ransac.py with a single c1-internal
helper at components/c1_vio/_facade_spine.py. Closes cumulative
review batches 52-54 Finding F1. No behaviour change — all existing
AZ-332 / AZ-333 / AZ-334 AC tests pass unmodified (114 c1_vio tests
green, 237 with adjacent regression suite).

The helper exposes 5 stateless free functions (now_iso, bias_norm,
se3_from_4x4, frame_ts_ns, frame_image) and a FacadeSpine mixin
class providing _classify_state / _tick_lost / _emit_transition.
Concrete strategies inherit the mixin and set spine-required
instance attributes in __init__. Mirrors the AZ-527 precedent for
c2_vpr-side _assert_engine_output_dim consolidation.

New test file test_az528_facade_spine.py covers AC-1..AC-8 with 19
tests, including an AST regression guard that prevents future
re-introduction of the consolidated free functions in any strategy
module, plus a Risk-1 static check that every strategy's __init__
assigns every spine-required attribute.

Archive AZ-528 task spec to done/, bump autodev state to batch 56.

Co-authored-by: Cursor <cursoragent@cursor.com>

_docs/_autodev_state.md

@@ -12,6 +12,6 @@ sub_step:
 retry_count: 0
 cycle: 1
 tracker: jira
-last_completed_batch: 54
+last_completed_batch: 55
 last_cumulative_review: batches_52-54
-current_batch: 55
+current_batch: 56