chore(road-editor): plan direct-edit task tree and add client test infra

Planning: parent design.md becomes the single authoritative contract
(constraint model with 6 kinds, handle manifest, coordinate/unit
layering, preview sequencing, storage layout and lazy migration, area
config snapshot, API contract). Work is split into four independently
verifiable child tasks with per-step gates and rollback points.

Test infra: pin vitest 4.1.11, add test:client:unit for client pure
logic, extend prettier globs to root *.ts so vitest.config.ts is checked.

Add .gitignore: the repo had none, so inputs/, outputs/, workbench-data/
and the client build output were untracked rather than ignored.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>

.trellis/tasks/08-26-direct-manipulation-road-editor/implement.jsonl

@@ -0,0 +1,8 @@
+{"file": ".trellis/spec/guides/cross-layer-thinking-guide.md", "reason": "本特性横跨 compiler / server / client 三层，新增 JSONL 文档、API 载荷与配置字段，正是该指南的触发条件"}
+{"file": ".trellis/spec/guides/code-reuse-thinking-guide.md", "reason": "米制换算必须复用 src/geometry/lane-geometry.js，v1 overrides 与 ID 校验必须复用而非另建一套"}
+{"file": ".trellis/tasks/08-26-direct-manipulation-road-editor/research/current-system.md", "reason": "现有可复用锚点、feature 回链字段与当前缺口清单"}
+{"file": ".trellis/tasks/08-26-direct-manipulation-road-editor/research/joint-solver.md", "reason": "求解阶段的插入点、依赖链顺序与约束不变量来源"}
+{"file": ".trellis/tasks/08-26-direct-manipulation-road-editor/research/canvas-integration.md", "reason": "输入 adapter 的候选、ol-ext 探针退出条件与回退优先级"}
+{"file": ".trellis/tasks/08-26-direct-manipulation-road-editor/research/revisions.md", "reason": "revision manifest 字段与重导入冲突体验的来源"}
+{"file": ".trellis/tasks/08-26-direct-manipulation-road-editor/research/junction-tools.md", "reason": "JunctionTools 的会话边界、预览/应用/保存状态与路口所有权划分"}
+{"file": ".trellis/tasks/08-26-direct-manipulation-road-editor/research/data-model-options.md", "reason": "三种数据模型的比较背景与选择理由；kind 枚举以 design.md 为准"}