diff --git a/.trellis/tasks/archive/2026-08/08-11-asset-package-contract/check.jsonl b/.trellis/tasks/archive/2026-08/08-11-asset-package-contract/check.jsonl
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+{"file":".trellis/spec/pipeline/cli-and-stages.md","reason":"Verify package stage ordering, manifest freshness, and external-tool boundaries."}
+{"file":".trellis/spec/config/index.md","reason":"Verify all new output paths remain centralized in area-config."}
+{"file":".trellis/spec/preview/index.md","reason":"Verify preview remains a consumer of package assets, not part of the published package."}
+{"file":".trellis/spec/guides/artifact-parity-guide.md","reason":"Assess intentional output-contract changes and asset verification scope."}
diff --git a/.trellis/tasks/archive/2026-08/08-11-asset-package-contract/design.md b/.trellis/tasks/archive/2026-08/08-11-asset-package-contract/design.md
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+# Asset Package Contract Design
+
+## Product Boundary
+
+`outputs/<area-id>/` remains the build workspace. Its `package/` child is the only
+publishable subtree and may be copied unchanged to another project. The package has
+no dependency on the parent directory, repository checkout, absolute local paths,
+QGIS, Blender, or the Cesium preview.
+
+```
+outputs/<area-id>/
+  package/                         # publishable boundary
+    manifest.json                   # asset-package/v1
+    models/
+      <area-id>.glb                 # compressed complete static scene
+      roads.glb
+      buildings.glb
+      vegetation.glb
+      water.glb
+  <area-id>-cesium-preview.html     # local verification only
+  _preview/                         # vehicles, routes, dynamic signal runtime
+  _pipeline/                        # staging, manifests and build diagnostics
+  osm2streets_web_out/, *.gpkg, *.qgz, *.blend, *.png
+```
+
+The package does not duplicate the GLBs: Cesium export and compression target the
+package model paths. Build staging lives under `_pipeline/` and is removed before a
+successful package is published.
+
+## Manifest v1
+
+The JSON root uses `schema: "osm-asset-package/v1"`. Required top-level fields are:
+
+| Field | Contract |
+|---|---|
+| `schema`, `packageVersion`, `areaId` | Stable identity and schema evolution point |
+| `coordinateSystem` | Literal local ENU contract: X east, Y north, Z up, meters |
+| `placement` | WGS84 anchor longitude/latitude/height plus heading correction degrees |
+| `bounds` | WGS84 `minLon`, `minLat`, `maxLon`, `maxLat` |
+| `assets` | Deterministic list of declared publishable assets |
+| `sceneStats` | Optional descriptive OSM-derived counts, not loading-critical |
+
+Each asset has `id`, `role`, `category`, `uri`, and `defaultLoad`. `uri` is a
+forward-slash relative path inside `package/`; it must not be absolute, start with
+`/`, contain `..`, or resolve outside the package. Roles are `scene` for the complete
+static scene and `layer` for separately loadable semantic subsets. Categories are
+fixed in v1: `scene`, `roads`, `buildings`, `vegetation`, `water`.
+
+`models/<area-id>.glb` is the only `scene` entry and defaults to load. Layer GLBs are
+optional alternatives for selective loading and default off; consumers must not load
+both the complete scene and overlapping layers unless intentionally composing them.
+
+The manifest deliberately excludes `source_osm`, `source_geojson`, arbitrary Cesium
+JavaScript, vehicle routes, vehicle models, dynamic signal states, countdown models,
+preview runtime paths, build timestamps and desktop paths. File digests and sizes may
+be added under an optional `integrity` object only after they are computed from final
+compressed files.
+
+## Pipeline Design
+
+### 1. Static export seed
+
+`blender/export_cesium.py` continues to own static GLB generation, WGS84 bounds,
+anchor and semantic collection selection. It must emit data suitable for a manifest
+seed, not a preview metadata document. Static traffic-signal geometry already in the
+main scene remains part of the static scene; animated traffic signal and countdown
+collections are not package assets.
+
+### 2. Package staging and compression
+
+The build orchestrator owns output paths through `normalizeAreaConfig()`. It adds
+explicit package paths and exports static GLBs to a package staging directory beneath
+`_pipeline/`. Compression works only on staged package files and rewrites the staged
+manifest's main GLB URI after successful compression. It never needs to copy or alter
+preview HTML.
+
+After path validation, file existence checks, and manifest validation, the package
+stage promotes the whole staging directory to `outputs/<area-id>/package/`. Promotion
+is directory-level and replaces a previous package only after the new one is valid.
+On failure, the previous published package remains usable and staging is retained or
+reported for diagnosis according to existing pipeline failure conventions.
+
+### 3. Preview adapter
+
+The existing Cesium preview remains a verification tool outside the package. It reads
+the package manifest via its relative path, then loads preview-only route, vehicle and
+dynamic-signal descriptors from `_preview/`. Dynamic traffic assets are declared in a
+preview-specific descriptor, never appended to package `assets`. This preserves
+existing high-precision cruise validation without making it a downstream requirement.
+
+### 4. Stage and compatibility behavior
+
+Canonical order becomes `intermediates/reimport -> blender -> cesium -> compress ->
+package -> preview`. `package` is included in the full default build and is callable
+explicitly to validate/publish existing staged static exports. `preview` stays an
+optional/verification stage, not a package dependency.
+
+Existing `npm run build:area -- --config ... --stages ...` remains supported. Root
+level legacy GLB/JSON/HTML files are not deleted by the migration; they are not read
+as a fallback by the new package contract. A clean full build produces the package as
+the canonical downstream asset source.
+
+## Consumer Examples
+
+Examples live in repository source, outside individual packages:
+
+- Cesium: fetch `manifest.json`, derive the ENU frame from `placement`, apply heading
+  correction, then load `assets` by `uri`.
+- Three.js: load the selected model URL relative to the manifest URL; expose the same
+  ENU placement object to the host application's georeferencing adapter. It must not
+  imply that Three.js alone converts ENU to WGS84.
+
+Both examples load the complete scene and demonstrate selecting a single `layer`.
+They validate that URLs are resolved relative to the manifest rather than the current
+page or repository root.
+
+## Validation and Rollback
+
+Unit tests validate schema fields, category/role legality, package-relative URI rules,
+and rejection of omitted/extra files. An integration fixture constructs a minimal
+package and verifies that Cesium and Three.js example resolvers choose identical
+relative URLs and placement values. A target-area package test checks final compressed
+GLB parsing and manifest references.
+
+The package stage writes a stage manifest containing only final published records and
+their integrity. Diagnostic checks distinguish missing package, invalid package, and
+stale package. Rollback is to the prior `package/` directory; legacy preview outputs
+remain untouched throughout rollout.
+
+## Deferred Decisions
+
+- Rich per-feature semantics, routing graph delivery and simulation inputs are not in
+  v1; they should be introduced through a later schema version only when a downstream
+  consumer requires them.
+- Asset coverage improvements are downstream of this contract work.
diff --git a/.trellis/tasks/archive/2026-08/08-11-asset-package-contract/implement.jsonl b/.trellis/tasks/archive/2026-08/08-11-asset-package-contract/implement.jsonl
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+++ b/.trellis/tasks/archive/2026-08/08-11-asset-package-contract/implement.jsonl
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+{"file":".trellis/spec/pipeline/cli-and-stages.md","reason":"Stage ordering, manifests, external-command boundary, and compression contracts."}
+{"file":".trellis/spec/config/index.md","reason":"Area output-path normalization and configuration contract."}
+{"file":".trellis/spec/preview/index.md","reason":"Preview config injection and browser runtime compatibility."}
+{"file":".trellis/spec/guides/cross-layer-thinking-guide.md","reason":"Blender-to-Node-to-browser coordinate and artifact contract risks."}
diff --git a/.trellis/tasks/archive/2026-08/08-11-asset-package-contract/implement.md b/.trellis/tasks/archive/2026-08/08-11-asset-package-contract/implement.md
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+# Asset Package Contract Implementation Plan
+
+## Phase 0: Contract Lock-In
+
+- [ ] Add a package-contract module that owns v1 schema constants, allowed roles and
+  categories, URI containment validation, manifest construction and validation.
+- [ ] Add focused unit fixtures for valid manifests and each invalid condition:
+  missing schema/placement/bounds, malformed coordinates, invalid role/category,
+  absolute or traversing URI, duplicate asset ID, missing primary scene, and referenced
+  file outside the package.
+- [ ] Document `package/` as the sole downstream boundary in README and pipeline/config
+  specs; retain a clear distinction between release assets and preview artifacts.
+
+Gate: manifest v1 can be created and structurally validated without invoking Blender,
+Cesium or QGIS.
+
+## Phase 1: Package Paths and Static Export
+
+- [ ] Extend `scripts/lib/area-config.js` with paths for `packageDir`, package manifest,
+  package model directory, primary GLB and semantic layer GLBs; keep all path derivation
+  in this module.
+- [ ] Change `blender/export_cesium.py` metadata output to a static manifest seed:
+  bounds, ENU placement and static scene/layer declarations only. Remove local source
+  paths and inline Cesium source code from the published data.
+- [ ] Direct static GLB output to package staging paths and retain dynamic signal/countdown
+  output as preview-only paths outside package staging.
+- [ ] Update `build-area.js`, semantic asset checks, stage manifests and diagnostics to
+  consume the new path contract rather than constructing paths locally.
+
+Gate: a Cesium export produces a valid static manifest seed and every declared static
+asset exists under package staging; no preview-only asset appears in it.
+
+## Phase 2: Compression and Atomic Publication
+
+- [ ] Refactor the default compression stage to operate on staged package files,
+  preserving the final manifest shape while replacing only the primary GLB bytes and
+  integrity data.
+- [ ] Add a `package` stage after `compress`; validate every asset and atomically promote
+  staging to `outputs/<area-id>/package/`.
+- [ ] Update canonical stage ordering, `all`, interactive CLI labels and defaults.
+- [ ] Ensure a failed compression/package validation never replaces an existing published
+  package; record diagnostics sufficient to identify the failed source/staging path.
+
+Gate: a full build creates one publishable package with compressed primary GLB and no
+duplicate static GLBs at the area root.
+
+## Phase 3: Preview Adapter and Compatibility
+
+- [ ] Change preview HTML generation to reference `package/manifest.json` relative to
+  the area output root.
+- [ ] Move route/vehicle/dynamic-signal discovery into a preview-only descriptor beneath
+  `_preview/`, and make `cesium-preview.js` merge it after loading the package manifest.
+- [ ] Preserve existing preview controls and graceful behavior when preview-only data is
+  absent; preview must still render the package static scene.
+- [ ] Update `diagnose:area`, `check:area` and stage manifest freshness to distinguish
+  package artifacts from preview-only files.
+
+Gate: the local Cesium preview loads the published package and continues to show
+optional cruise/dynamic preview content without adding either to package manifest.
+
+## Phase 4: Downstream Consumption Proof
+
+- [ ] Add Cesium example code that resolves the manifest URL, validates placement and
+  loads the full scene or selected layers.
+- [ ] Add Three.js example code with a manifest-relative resolver and an explicit ENU
+  placement handoff to the host's georeferencing integration.
+- [ ] Add automated resolver tests so neither example can regress to page-relative,
+  desktop-absolute or repository-relative URLs.
+- [ ] Publish consumer documentation including overlap rules for complete scene vs layers.
+
+Gate: examples run from a copied `package/` directory and require no files outside it.
+
+## Phase 5: Full Verification and Migration
+
+- [ ] Run focused Node tests for package schema, stage resolution, compression metadata,
+  preview behavior, diagnostics and asset budgets.
+- [ ] Run the full default build for the primary area, then `check:area` and package
+  integrity validation.
+- [ ] Inspect the packaged GLB structure and validate the Cesium example in browser;
+  verify Three.js resolver output with the same manifest.
+- [ ] Capture expected intentional output-contract changes in docs/changelog and update
+  relevant Trellis pipeline/config/preview specs.
+- [ ] Preserve legacy root-level artifacts during rollout; document that downstream
+  consumers must migrate to `package/manifest.json` rather than treating legacy files
+  as fallback.
+
+## High-Risk Boundaries
+
+- `blender/export_cesium.py` to Node: static metadata fields and semantic asset file
+  names are a cross-runtime contract.
+- Node packaging to preview runtime: preview-only dynamic data must never silently enter
+  the package manifest.
+- Compression to publication: paths must remain package-relative and a partial write must
+  not replace the last valid package.
+- Consumers: ENU axes and heading correction are load-bearing; examples must not create
+  a second, incompatible georeferencing convention.
+
+## Validation Commands
+
+```bash
+npm run test:build-stages
+npm run test:compress-glb
+npm run test:preview-assets
+npm run test:budgets
+npm run test:preflight
+npm run check:area -- --config config/areas/nantaizi-lake-innovation-valley.json
+node scripts/glb-digest.js outputs/nantaizi-lake-innovation-valley/package/models/nantaizi-lake-innovation-valley.glb
+```
diff --git a/.trellis/tasks/archive/2026-08/08-11-asset-package-contract/prd.md b/.trellis/tasks/archive/2026-08/08-11-asset-package-contract/prd.md
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+# Reusable asset package contract
+
+## Goal
+
+将当前面向 Cesium 预览的区域输出升级为可由多个下游项目稳定消费的静态资产包。资产包
+必须有版本化 manifest、仅使用包内相对引用，并明确发布资产与本项目调试/预览产物的边界。
+
+## Confirmed Facts
+
+- `blender/export_cesium.py` 已生成 `<area>.json`，包含主 GLB、roads/buildings/
+  vegetation/water 分层 GLB、WGS84 anchor、ENU 坐标约定、heading correction 和 OSM bounds。
+- 该 JSON 同时包含桌面绝对 `source_osm` / `source_geojson` 路径、Cesium 代码片段，以及
+  动态信号灯和倒计时预览资产；因此不是可发布的下游契约。
+- `outputs/<area>/` 还包含 QGIS、GeoJSON、Blender、Cesium HTML/runtime、车辆巡航和自检文件；
+  它是构建工作目录，不是干净的发布目录。
+- 当前默认 Cesium GLB 已在构建末端压缩，且 metadata 中的资产 URL 使用同目录相对文件名。
+- 项目目标是生成可复用资产；交通仿真、跟车和信号调度属于下游运行时能力，不属于资产包首版。
+
+## Requirements
+
+- R1：定义一个版本化 `manifest.json` v1，描述区域 ID、WGS84 anchor、ENU 轴向与 heading
+  correction、WGS84 bounds、发布资产、语义类别和包内相对路径。
+- R2：资产包只含可复用的静态交付资产；主场景和道路、建筑、植被、水体等分层模型必须有
+  明确的角色、加载语义和默认行为。
+- R3：manifest 和包内文件不得包含桌面绝对路径、构建临时目录、Cesium HTML/runtime、
+  QGIS、GeoJSON、`.blend`、车辆巡航或动态交通信号调度依赖。
+- R4：在不破坏现有区域预览、诊断和构建中间产物的前提下，增加明确的资产包发布阶段。
+- R5：提供 Cesium 与 Three.js 的最小加载示例，均从 manifest 读取包内相对 URL，并按相同的
+  WGS84/ENU 契约放置主场景或分层资产。
+- R6：定义发布资产、可选静态资产和本项目仅检查产物的分类规则，并由测试验证。
+- R7：完整构建后的资产包应可独立复制到其他项目，而无需本仓库的 `outputs` 目录结构或本地路径。
+
+## Acceptance Criteria
+
+- [ ] 目标区域生成一个可独立分发的资产包目录，其中仅有 manifest 和 manifest 引用的发布资产。
+- [ ] manifest 的 schema version、坐标契约、bounds、所有资产类别和 URL 可由程序校验。
+- [ ] 所有 manifest URL 都是安全的包内相对路径；不得含绝对路径、`..` 或未声明文件。
+- [ ] 主 GLB 与每个发布分层资产都能在 Cesium 和 Three.js 示例中按 manifest 正确放置与加载。
+- [ ] 车辆、巡航路线、Cesium preview HTML/runtime、QGIS/GeoJSON/`.blend` 和动态信号调度资产
+  不会进入发布包。
+- [ ] 既有 `outputs/<area>/` 预览工作流继续可用，现有非交互 build 命令保持兼容。
+- [ ] 发布包缺文件、manifest 路径越界、坐标字段无效或资产类别不合法时，构建/校验非零退出。
+
+## Proposed Delivery Phases
+
+1. 契约与目录边界：冻结 manifest v1 schema、发布目录结构、资产角色和坐标定义。
+2. 资产包发布阶段：从现有 Cesium 导出与压缩结果收集、校验并写入独立包目录。
+3. 下游消费证明：Cesium / Three.js 示例仅依赖 manifest 与包内容，并覆盖主场景和按类别加载。
+4. 质量门与迁移：增加结构、路径隔离、坐标和加载验证；保留旧预览输出并记录迁移规则。
+
+## Key Decision
+
+- 发布包根目录固定为 `outputs/<area-id>/package/`。该目录是可整体复制给下游项目的唯一
+  发布边界；GLB 和 manifest 直接生成或移动到这里，避免与工作目录再保留一套大模型副本。
+  本项目的预览页可通过包内相对路径读取发布资产，但 HTML/runtime 本身不属于发布包。
+
+## Out Of Scope
+
+- 交通流、车辆行为、信号相位控制、路口调度和其他运行时仿真。
+- 在本任务中扩展 OSM 到建筑、路灯、标志、植被等资产覆盖率或生成质量。
+- 删除既有 `outputs/<area>/` 中由用户保留的历史调试产物。
diff --git a/.trellis/tasks/archive/2026-08/08-11-asset-package-contract/task.json b/.trellis/tasks/archive/2026-08/08-11-asset-package-contract/task.json
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+++ b/.trellis/tasks/archive/2026-08/08-11-asset-package-contract/task.json
@@ -0,0 +1,26 @@
+{
+  "id": "asset-package-contract",
+  "name": "asset-package-contract",
+  "title": "Reusable asset package contract",
+  "description": "",
+  "status": "completed",
+  "dev_type": null,
+  "scope": null,
+  "package": null,
+  "priority": "P2",
+  "creator": "dingkang",
+  "assignee": "dingkang",
+  "createdAt": "2026-08-11",
+  "completedAt": "2026-08-12",
+  "branch": null,
+  "base_branch": "main",
+  "worktree_path": null,
+  "commit": null,
+  "pr_url": null,
+  "subtasks": [],
+  "children": [],
+  "parent": null,
+  "relatedFiles": [],
+  "notes": "",
+  "meta": {}
+}
\ No newline at end of file