[AZ-812] Region API: rename Latitude/Longitude → Lat/Lon (OSM convention)

Mirror of AZ-794 (inventory z/x/y rename). RequestRegionRequest.cs renames C#
props Latitude→Lat / Longitude→Lon and adds [JsonPropertyName("lat"/"lon")] so
the wire format is unambiguous under the AZ-795 strict-parsing stack
(UnmappedMemberHandling.Disallow → legacy {"latitude":..,"longitude":..} now
returns HTTP 400 instead of silently coercing).

Updates all in-repo consumers: API handler (Program.cs), integration tests
(Models.cs, RegionTests.cs, IdempotentPostTests.cs, SecurityTests.cs), the
performance harness (run-performance-tests.sh PT-03/04/05/07), and module
docs (common_dtos.md, api_program.md; system-flows.md F2 already used
lat/lon). New RegionFieldRenameTests.cs covers AC-4 both directions (new
format → 200, legacy format → 400). Smoke green; no regressions.

region-request.md contract doc not bumped here — AZ-808 publishes v1.0.0
directly with the post-rename names per AZ-812 coordination clause.

Batch 01 of cycle 8. PASS_WITH_WARNINGS (one Low DRY finding for follow-up
test-helper consolidation; details in
_docs/03_implementation/reviews/batch_01_cycle8_review.md).

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

_docs/03_implementation/reviews/batch_01_cycle8_review.md

@@ -0,0 +1,70 @@
+# Code Review Report
+
+**Batch**: 01 (cycle 8)
+**Tasks**: AZ-812 (Region API field rename Latitude/Longitude → Lat/Lon, OSM convention)
+**Date**: 2026-05-22
+**Verdict**: PASS_WITH_WARNINGS
+
+## Findings
+
+| # | Severity | Category | File:Line | Title |
+|---|----------|----------|-----------|-------|
+| 1 | Low | Maintainability | `SatelliteProvider.IntegrationTests/RegionFieldRenameTests.cs:79` | `AssertErrorsContainsMention` copy-pasted from `TileInventoryValidationTests.cs` |
+
+### Finding Details
+
+**F1: `AssertErrorsContainsMention` copy-pasted from `TileInventoryValidationTests.cs`** (Low / Maintainability)
+- Location: `SatelliteProvider.IntegrationTests/RegionFieldRenameTests.cs:79-110` (and the prior copy at `TileInventoryValidationTests.cs:396-428`)
+- Description: The new `RegionFieldRenameTests.cs` copies the private `AssertErrorsContainsMention` helper verbatim from `TileInventoryValidationTests.cs`. Both helpers walk the same `errors` object and assert a mention exists in either keys or messages.
+- Suggestion: Promote the helper to `ProblemDetailsAssertions.cs` (the natural home for cross-test ProblemDetails assertions) and migrate both tests in a small follow-up cleanup. NOT done in this batch — touching the cycle-7 file is out of AZ-812 scope. Tracked as future hygiene, not a regression.
+- Task: AZ-812
+
+## Phase Summary
+
+| Phase | Outcome |
+|-------|---------|
+| 1. Context Loading | Read AZ-812 spec + `_docs/02_document/module-layout.md`. Scope is the Region POST DTO rename. |
+| 2. Spec Compliance | AC-1 ✓ (DTO has Lat/Lon + JsonPropertyName), AC-2 ✓ (wire format end-to-end with `lat`/`lon`), AC-3 ✓ (`RegionTests.cs` happy-path updated), AC-4 ✓ (`RegionFieldRenameTests` validates both directions, smoke green), AC-5 ✓ (common_dtos.md, api_program.md, system-flows.md updated/verified), AC-6 ✓ (`region-request.md` does not yet exist — AZ-808 will publish v1.0.0 directly with new names per spec coordination). No Spec-Gap. |
+| 3. Code Quality | Mechanical DTO rename, clean. One DRY violation (F1) — Low severity. |
+| 4. Security | No SQL injection, no hardcoded secrets, no sensitive data in logs. New test uses GUID + test coordinates only. |
+| 5. Performance | No perf impact (field rename). No N+1, no blocking I/O. |
+| 6. Cross-Task Consistency | Single-task batch — N/A. |
+| 7. Architecture Compliance | DTO in `SatelliteProvider.Common/DTO/` (Common layer, importable by all). Test in `SatelliteProvider.IntegrationTests/` (test layer). No layering violations, no cycles, no Public-API bypasses, no ADR violations. |
+
+## Files Reviewed
+
+- `SatelliteProvider.Common/DTO/RequestRegionRequest.cs` (DTO rename + `[JsonPropertyName]` attrs)
+- `SatelliteProvider.Api/Program.cs` (handler property access updated)
+- `SatelliteProvider.IntegrationTests/Models.cs` (test-side DTO mirror updated)
+- `SatelliteProvider.IntegrationTests/RegionTests.cs` (happy-path uses new property names)
+- `SatelliteProvider.IntegrationTests/IdempotentPostTests.cs` (JSON payload `lat`/`lon`)
+- `SatelliteProvider.IntegrationTests/SecurityTests.cs` (JSON payload `lat`/`lon`)
+- `SatelliteProvider.IntegrationTests/RegionFieldRenameTests.cs` (new — AZ-812 AC-4 coverage)
+- `SatelliteProvider.IntegrationTests/Program.cs` (smoke + full suite wired to call `RegionFieldRenameTests.RunAll`)
+- `scripts/run-performance-tests.sh` (PT-03/04/05/07 JSON bodies updated to `lat`/`lon`)
+- `_docs/02_document/modules/common_dtos.md` (RequestRegionRequest section added; RegionRequest disambiguated as internal queue type)
+- `_docs/02_document/modules/api_program.md` (RequestRegionRequest moved from Local Records to Common/DTO section)
+
+## Test Evidence
+
+`./scripts/run-tests.sh --smoke` (`integration-tests` container exit code 0):
+
+```
+Test: Region endpoint OSM field-name rename (AZ-812)
+====================================================
+
+AZ-812 AC-4 (positive): new {lat,lon} wire format → HTTP 200
+  ✓ {lat,lon} body accepted with HTTP 200
+
+AZ-812 AC-4 (negative): legacy {latitude,longitude} wire format → HTTP 400 (UnmappedMemberHandling.Disallow)
+  ✓ Legacy {latitude,longitude} body rejected with HTTP 400; errors map names the unknown field
+✓ Region field-rename tests: PASSED
+```
+
+No regressions: cycle-7 inventory validation suite, idempotent POST, security, route, tile, leaflet path, and migrations 012/013/014 all green in the same smoke run.
+
+## Verdict Logic
+
+- No Critical, no High, no Medium findings.
+- 1 Low finding (DRY in test helpers) — does not block.
+- **PASS_WITH_WARNINGS**.