refactor: move road compiler core into package

.trellis/tasks/08-25-rc-p1-package-boundary/design.md

@@ -0,0 +1,53 @@
+# Phase 1 Technical Design
+
+## Boundary
+
+`packages/road-compiler/` becomes the single implementation owner for native
+road compilation. It is a CommonJS workspace package with explicit public
+entrypoints for compiler APIs, traffic-signal schema, turn-lane helpers, OSM
+parsing, reference conversion, and CLIs. It never imports `area-config`, reads
+`config/areas`, or derives host paths.
+
+The host owns `scripts/lib/area-config.js` and maps normalized configuration to
+the v1 `RoadCompilerInput` shape using `toRoadCompilerInput(area)`. During P1,
+`build-area.js` calls the package in-process; P2 is the only phase that changes
+that call to a child process.
+
+## Source Ownership and Compatibility
+
+The following current `scripts/lib` implementations move into package `src`:
+`native-road`, `complex-junction`, `turn-lane-arrows`, `lane-geometry`,
+`gaode-junction-reference`, `native-traffic-signals`, and `osm`.
+
+Some moved modules also serve legacy host paths: QGIS uses turn-lane arrows,
+vehicle preview and reimport use OSM parsing, and preview tests use lane
+geometry. Those consumers import the package entrypoints after the move. This
+preserves one implementation while allowing host -> package dependency.
+
+Traffic signal ownership follows the matrix in
+`research/traffic-signals-split-matrix.md`: schema, geometry, validation, and
+runtime construction move to the package. The host retains only two file-I/O
+adapters, `readTrafficSignalFeatures()` and `readTrafficSignals()`, both
+delegating to package exports. No duplicated schema code remains.
+
+## Input and Path Handling
+
+The package compiler API accepts only `RoadCompilerInput` from
+`docs/native-road-package-v1.md`. Package CLI commands accept an explicit JSON
+input file (`--input`) and never load area configuration. The compatibility
+host CLI still accepts `--config`, but immediately maps it through
+`toRoadCompilerInput()` before entering the package.
+
+`junctionTemplates.*.referenceFile` changes to a path relative to its area
+configuration. `readAreaConfig()` resolves it while normalizing configuration;
+the package receives an absolute path and does no path resolution.
+
+## Tests and Rollout
+
+The package receives the required Fengshu OSM fixture plus migrated unit tests.
+Its `npm test` must run from the package directory without reading host inputs
+or outputs. After each source batch, run the two Phase 0 parity baselines. The
+existing host command names remain compatibility wrappers through P1.
+
+Rollback is a normal Git revert of the latest batch commit. No module has a
+parallel host copy after its batch lands, preventing divergence.

.trellis/tasks/08-25-rc-p1-package-boundary/implement.md

@@ -6,13 +6,13 @@
 
 ```bash
 # 基线必须先绿
-for a in fengshu-er-road hanyang-block nantaizi-lake-innovation-valley; do
+for a in fengshu-er-road nantaizi-lake-innovation-valley; do
   node scripts/road-parity.js --config config/areas/$a.json \
     --compare .trellis/tasks/08-25-road-compiler-extraction/baseline/$a.json || echo "FAIL $a"
 done
 ```
 
-- [ ] 三区域基线全绿（否则回 Phase 0）
+- [ ] 两个有效区域基线全绿（否则回 Phase 0）
 
 ## Step 1 — K1 矩阵（动代码之前）
 
@@ -89,7 +89,7 @@ packages/road-compiler/
 
 ```bash
 # parity
-for a in fengshu-er-road hanyang-block nantaizi-lake-innovation-valley; do
+for a in fengshu-er-road nantaizi-lake-innovation-valley; do
   node scripts/road-parity.js --config config/areas/$a.json \
     --compare .trellis/tasks/08-25-road-compiler-extraction/baseline/$a.json || echo "FAIL $a"
 done

.trellis/tasks/08-25-rc-p1-package-boundary/prd.md

@@ -66,9 +66,9 @@
 
 ## Acceptance Criteria
 
-- [ ] AC1.1 三区域 `road-parity --compare` 对 Phase 0 基线全绿
+- [ ] AC1.1 两个有效区域 `road-parity --compare` 对 Phase 0 基线全绿
 - [ ] AC1.2 `npm run test:native-road`、`npm run test:road-workbench` 通过
-- [ ] AC1.3 `npm run build:area` 三区域完整跑通（含 blender / cesium 阶段）
+- [ ] AC1.3 `npm run build:area` 枫树二路完整跑通（含 blender / cesium 阶段）
 - [ ] AC1.4 `grep -rn "area-config\|config/areas" packages/road-compiler/` 无命中
 - [ ] AC1.5 `packages/road-compiler/` 内 `npm test` 不访问宿主 `inputs/` 或 `outputs/`
 - [ ] AC1.6 `scripts/lib/` 下无搬迁文件的残留副本

.trellis/tasks/08-25-rc-p1-package-boundary/research/traffic-signals-split-matrix.md

@@ -0,0 +1,21 @@
+# Traffic Signals Split Matrix
+
+Evidence gathered from `scripts/lib/traffic-signals.js` and repository-wide
+call-site search on 2026-08-25.
+
+| Export | Current users | Owner after P1 | Migration |
+|---|---|---|---|
+| `SIGNAL_LAYOUT` | `buildTrafficSignalsFromFeatures` | compiler package | Export from `@osm-asset/road-compiler/traffic-signals` |
+| `signalNodeKey` | `buildTrafficSignalsFromFeatures` | compiler package | No host caller today; preserve public export for runtime identity contract |
+| `buildTrafficSignalFeatures` | `native-traffic-signals`, `readTrafficSignalFeatures` | compiler package | Host QGIS adapter imports it from the package |
+| `validateTrafficSignalFeatures` | `native-traffic-signals`, signal tests | compiler package | Tests import package entrypoint |
+| `validateTrafficSignalSourceReferences` | `native-traffic-signals`, `reimport-gpkg`, `readTrafficSignals` | compiler package | Reimport adapter imports package function |
+| `buildTrafficSignalsFromFeatures` | `native-traffic-signals`, `readTrafficSignals`, `buildTrafficSignals` | compiler package | Host preview adapter imports package function |
+| `buildTrafficSignals` | `test-preview-assets` | compiler package | Test imports package function; it is geometry/schema behavior, not host I/O |
+| `readTrafficSignalFeatures` | `build-osm2streets-qgis` | host adapter | Keep a thin file-reading wrapper under `scripts/lib/traffic-signals.js`; it imports package functions |
+| `readTrafficSignals` | `build-area` | host adapter | Keep a thin file-reading wrapper under `scripts/lib/traffic-signals.js`; it imports package functions |
+
+`scripts/lib/traffic-signals.js` must not retain a second implementation of
+the schema or geometry. Its only P1 responsibility is host file I/O for the
+legacy QGIS / preview paths. This preserves the one-way dependency:
+host -> compiler package; the package never imports the host.

.trellis/tasks/08-25-rc-p1-package-boundary/task.json

@@ -3,7 +3,7 @@
   "name": "rc-p1-package-boundary",
   "title": "Phase 1：包边界（不换仓库）",
   "description": "在本仓库内建 packages/road-compiler，移入编译器模块，用窄输入契约替换 readAreaConfig 耦合，产物对基线逐字节一致",
-  "status": "planning",
+  "status": "in_progress",
   "dev_type": null,
   "scope": null,
   "package": null,