[AZ-371] Refactor C18: magic numbers to ProcessingConfig/MapConfig

Promotes 8 operational levers into config keys with defaults that match
the prior source literals byte-for-byte:
  ProcessingConfig: RegionProcessingTimeoutSeconds (300),
  RouteProcessingPollIntervalSeconds (5),
  MaxRoutePointSpacingMeters (200), LatLonTolerance (0.0001).
  MapConfig: TileSizePixels (256), AllowedZoomLevels ([15..19]),
  RetryBaseDelaySeconds (1), RetryMaxDelaySeconds (30).

Sites updated: RegionService, RouteProcessingService,
RoutePointGraphBuilder, RouteValidator, RouteService 4-arg ctor,
RouteImageRenderer, GoogleMapsDownloaderV2, TileService. Closes LF-2 by
forwarding HttpContext.RequestAborted from GetTileByLatLon into the
downloader. appsettings.json gains the 8 new keys at default values.

Tests: 141 / 141 unit + 5 / 5 smoke green. New ConfigDefaultsTests pins
defaults to original literals; new TileService unit test asserts CT
identity from caller to downloader (AZ-371 AC-3).

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

_docs/03_implementation/batch_18_report.md

@@ -0,0 +1,178 @@
+# Batch 18 Report — Refactor 03 Phase 4 (kickoff)
+
+Date: 2026-05-11
+Epic: AZ-350 (03-code-quality-refactoring)
+Status: ✅ Complete
+
+## Scope (1 task / 3 SP)
+
+| ID | C-ID | Title | Points | Component |
+|----|------|-------|--------|-----------|
+| AZ-371 | C18 | Move hardcoded magic numbers to ProcessingConfig / MapConfig | 3 | Common + Services.* (all) |
+
+Solo batch. First task of Phase 4 (typing/config/tooling). Promotes operational
+literals scattered across 5 service files into explicit `ProcessingConfig` /
+`MapConfig` keys. Defaults preserve every prior runtime value byte-for-byte.
+Also closes the LF-2 finding by forwarding `HttpContext.RequestAborted` from
+`GetTileByLatLon` into the downloader.
+
+## Changes
+
+### Production
+
+- **MODIFIED** `SatelliteProvider.Common/Configs/ProcessingConfig.cs`
+  - Added 4 keys with defaults that match prior source literals:
+    - `RegionProcessingTimeoutSeconds = 300` (was `TimeSpan.FromMinutes(5)`)
+    - `RouteProcessingPollIntervalSeconds = 5` (was `TimeSpan.FromSeconds(5)`)
+    - `MaxRoutePointSpacingMeters = 200.0` (was the `public const`)
+    - `LatLonTolerance = 0.0001` (was duplicated in 2 sites)
+
+- **MODIFIED** `SatelliteProvider.Common/Configs/MapConfig.cs`
+  - Added 4 keys with defaults that match prior source literals:
+    - `TileSizePixels = 256`
+    - `AllowedZoomLevels = [15, 16, 17, 18, 19]`
+    - `RetryBaseDelaySeconds = 1`
+    - `RetryMaxDelaySeconds = 30`
+
+- **MODIFIED** `SatelliteProvider.Api/appsettings.json`
+  - Added the 8 new keys under `MapConfig` and `ProcessingConfig`. Values match
+    `Common.Configs` defaults. `appsettings.Development.json` left untouched —
+    no environment-specific overrides for these levers yet.
+
+- **MODIFIED** `SatelliteProvider.Services.RegionProcessing/RegionService.cs`
+  - Constructor now takes `IOptions<ProcessingConfig> processingConfig`.
+  - The 5-minute region-processing timeout in `ProcessRegionAsync` is now
+    `TimeSpan.FromSeconds(_processingConfig.RegionProcessingTimeoutSeconds)`.
+
+- **MODIFIED** `SatelliteProvider.Services.RouteManagement/RouteProcessingService.cs`
+  - Constructor now takes `IOptions<ProcessingConfig> processingConfig`.
+  - `_checkInterval` is no longer a `readonly` initializer literal; it's
+    set in the constructor from the config.
+
+- **MODIFIED** `SatelliteProvider.Services.RouteManagement/RoutePointGraphBuilder.cs`
+  - Single ctor `(IOptions<ProcessingConfig>)`; the previous
+    parameterless ctor + `public const MaxPointSpacingMeters` are gone.
+  - The const lived briefly to replace the inline literal in `RouteService`
+    (batch 15); promoting it the rest of the way to config is the natural
+    completion of that move.
+
+- **MODIFIED** `SatelliteProvider.Services.RouteManagement/RouteValidator.cs`
+  - Constructor now requires `IOptions<ProcessingConfig>`; reads
+    `LatLonTolerance` once and reuses it for the polygon (0,0) check.
+  - `ValidatePolygon` is no longer `static` because it reads instance state.
+
+- **MODIFIED** `SatelliteProvider.Services.RouteManagement/RouteService.cs`
+  - The 4-arg DI ctor (`IRouteRepository, IRegionService, IOptions<ProcessingConfig>, ILogger`)
+    is the production-callable ctor; the chained 8-arg ctor used by the
+    decomposition still accepts the helpers directly. The 4-arg ctor
+    constructs `RouteValidator` and `RoutePointGraphBuilder` with the same
+    `IOptions<ProcessingConfig>` reference.
+
+- **MODIFIED** `SatelliteProvider.Services.RouteManagement/RouteImageRenderer.cs`
+  - **Adjacent hygiene**: the `private const int TileSizePixels = 256` that
+    was extracted from `RouteProcessingService` in batch 17 is now read from
+    `_mapConfig.TileSizePixels`. Same operational lever as the `TileService`
+    site — leaving one configurable and the other hardcoded would be an
+    immediate cumulative-review finding (cross-task duplicate).
+
+- **MODIFIED** `SatelliteProvider.Services.TileDownloader/GoogleMapsDownloaderV2.cs`
+  - The 4 `private const`s (`TILE_SIZE_PIXELS`, `MAX_RETRY_DELAY_SECONDS`,
+    `BASE_RETRY_DELAY_SECONDS`, `ALLOWED_ZOOM_LEVELS`) are gone.
+  - `MapConfig` was already injected; now `_mapConfig` field stores the
+    resolved `MapConfig.Value` and the 4 sites consume `_mapConfig.*`.
+  - `CalculateTileSizeInMeters` is no longer `static` (reads `_mapConfig`).
+  - The `0.0001` lat/lon tolerance in `GetTilesWithMetadataAsync` now reads
+    `_processingConfig.LatLonTolerance` once per call and reuses it in the
+    closure.
+
+- **MODIFIED** `SatelliteProvider.Services.TileDownloader/TileService.cs`
+  - Constructor now takes `IOptions<MapConfig> mapConfig`.
+  - `BuildTileEntity` becomes an instance method (reads `_mapConfig`); the
+    `TileSizePixels = 256` literal becomes `_mapConfig.TileSizePixels`.
+
+- **MODIFIED** `SatelliteProvider.Api/Program.cs`
+  - `GetTileByLatLon` now accepts `HttpContext httpContext` and forwards
+    `httpContext.RequestAborted` into `DownloadAndStoreSingleTileAsync`.
+  - This closes LF-2 (logical-flow finding from the discovery phase): client
+    cancellations now propagate through the `/api/satellite/tiles/latlon`
+    endpoint into the downloader.
+
+### Tests
+
+- **NEW** `SatelliteProvider.Tests/ConfigDefaultsTests.cs` — 7 tests that
+  pin the new config defaults to the original source literals (AC-2 evidence
+  — defaults preserve behavior is the load-bearing claim of this batch).
+- **MODIFIED** `SatelliteProvider.Tests/TileServiceTests.cs`
+  - Added 1 new test `DownloadAndStoreSingleTileAsync_ForwardsCancellationTokenToDownloader_AZ371_AC3`
+    (AC-3 evidence — caller-supplied CT reaches the downloader).
+  - Updated `BuildService` to construct `TileService` with the new
+    `IOptions<MapConfig>` argument.
+- **MODIFIED** `SatelliteProvider.Tests/InfrastructureTests.cs`
+  - Updated the `TileService_ConstructsWithMockedDependencies` smoke test to
+    provide the new `IOptions<MapConfig>`.
+- **MODIFIED** `SatelliteProvider.Tests/RegionServiceTests.cs`
+  - `BuildService` now also threads `IOptions<ProcessingConfig>`.
+- **MODIFIED** `SatelliteProvider.Tests/RouteServiceTests.cs`
+  - `BuildService` now also threads `IOptions<ProcessingConfig>`.
+- **MODIFIED** `SatelliteProvider.Tests/RoutePointGraphBuilderTests.cs`
+  - All 8 `new RoutePointGraphBuilder()` calls go through a `MakeBuilder()`
+    helper that wraps the new options ctor.
+  - The two assertions that referenced `RoutePointGraphBuilder.MaxPointSpacingMeters`
+    now read `DefaultProcessingConfig.MaxRoutePointSpacingMeters`.
+- **MODIFIED** `SatelliteProvider.Tests/RouteValidatorTests.cs`
+  - All 9 `new RouteValidator()` calls go through `MakeValidator()`.
+- **MODIFIED** `SatelliteProvider.Tests/RouteImageRendererTests.cs`
+  - `BuildSut` now also threads `IOptions<MapConfig>`.
+
+## Verification
+
+| Check | Result |
+|-------|--------|
+| Unit tests | ✅ 141 / 141 pass (was 133; +7 ConfigDefaultsTests, +1 AZ-371 AC-3 CT test) |
+| Integration smoke | ✅ All scenarios pass; exit 0 |
+| Behavior preservation | ✅ Defaults match prior literals byte-for-byte |
+| Linter | ✅ No findings on any modified file |
+
+## AC Coverage
+
+| AC | Evidence |
+|----|----------|
+| AC-1: All listed magic numbers replaced by config-bound values | Grep for `FromMinutes(5)`, `TILE_SIZE_PIXELS`, `MAX_RETRY`, `BASE_RETRY`, `ALLOWED_ZOOM`, `200.0`, `0.0001`, `TileSizePixels = 256` across `SatelliteProvider.Services.*/**/*.cs` returns no matches. The remaining `_tileSizePixels` references are `MapConfig`-bound. |
+| AC-2: Defaults preserve all existing behavior | `ConfigDefaultsTests` (7 tests) pins each new default to the original literal value. Smoke suite passes — region pipeline, route pipeline, tile downloads all behave identically. |
+| AC-3: `GetTileByLatLon` request cancellation flows into the downloader | `Program.cs:165` now passes `httpContext.RequestAborted` into `DownloadAndStoreSingleTileAsync`. `TileServiceTests.DownloadAndStoreSingleTileAsync_ForwardsCancellationTokenToDownloader_AZ371_AC3` captures the CT through the mock and asserts identity. |
+
+## Inline Code Review
+
+This batch is a config-binding refactor. The risk surface:
+
+1. **Default-value drift** — every default in `ProcessingConfig` and `MapConfig`
+   was set side-by-side with the original literal in source and verified by
+   `ConfigDefaultsTests`. No drift possible.
+2. **Constructor fan-out** — 5 production classes gained ctor params. Only the
+   already-DI-resolved consumers (`RouteService` 4-arg, `RegionService`,
+   `TileService`, `RouteProcessingService`, `GoogleMapsDownloaderV2`) needed
+   `IServiceCollection` calls — and those are unchanged because the existing
+   `services.AddSingleton(...)` lines bind via reflection. The two helper
+   classes that tests `new` directly (`RouteValidator`, `RoutePointGraphBuilder`)
+   now require `IOptions<ProcessingConfig>` — every call site is updated.
+3. **Static → instance demotions** — three methods became instance methods
+   (`TileService.BuildTileEntity`, `GoogleMapsDownloaderV2.CalculateTileSizeInMeters`,
+   `RouteValidator.ValidatePolygon`). Each one now reads instance state, so
+   the demotion is correct per `coderule.mdc` ("Only use static methods for
+   pure, self-contained computations").
+4. **CT plumbing** (LF-2) — endpoint local function gained `HttpContext`
+   parameter; minimal API binding picks it up automatically. Smoke covers
+   the happy path; the new unit test pins the contract on `TileService`.
+
+**Verdict: PASS.** No findings. Behavior preserved end-to-end.
+
+## State
+
+`auto_push: true`. After this commit lands, transitions on AZ-371 → In Testing
+in Jira and the task file moves from `todo/` to `done/`. Batch 18 closes the
+window for the cumulative K=3 review covering batches 16–18 — that runs next.
+
+## Next Batch (preview)
+
+Phase 4 ordering: AZ-370 (status / point-type enums + AC RT2 update, 3 SP).
+After the cumulative K=3 review for 16–18.