[AZ-810] Clamp UAV test-fixture coordinates to OSM-valid range

The AZ-810 metadata validator rejects lat outside [-90, 90] and lon
outside [-180, 180]. Two NextTestCoordinate() helpers seeded their
counter from `(Ticks/TicksPerSecond) % 1_000_000` and returned
`60 + n*0.0005`, producing lat well above 90° for almost any seed
(e.g. n=200000 -> lat=160). Pre-AZ-810 there was no validator and no
DB constraint, so the out-of-range values were silently accepted; the
new validator (correctly) rejected them at HTTP 400.

Clamp both helpers to non-overlapping OSM-valid ranges:
  - UavUploadTests.cs:           lat in [50, 70),  lon in [10, 40)
  - UavUploadValidationTests.cs: lat in [-70, -50), lon in [-40, -10)

Non-overlap (not the prior +5_000_000 counter offset) is what now
guarantees AZ-488 and AZ-810 suites don't collide on the per-source
UNIQUE index when both run against the same DB.

No production code change; AZ-810 validator behaviour is unchanged.

Also:
- Correct AC-9 in batch_04_cycle8_report.md: the original claim
  ("verified by tracing source") was a false-PASS; the autodev
  Step 11 test run surfaced the gap. Now confirmed by full-suite
  green (scripts/run-tests.sh --full).
- Add ring-buffer lesson on AC-verification standards for input-
  validation changes: tracing fixture variables to their generators
  is insufficient; only a green integration-test run is sound
  evidence for a "no-regression" AC.

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

_docs/_autodev_state.md

@@ -4,12 +4,12 @@
 flow: existing-code
 step: 11
 name: Run Tests
-status: not_started
+status: in_progress
 sub_step:
-  phase: 0
-  name: awaiting-invocation
-  detail: ""
-retry_count: 0
+  phase: 2
+  name: run-tests
+  detail: "re-run after coord-clamp fix"
+retry_count: 1
 cycle: 8
 tracker: jira
 auto_push: true