fix(workflows): remove background launch alias

[seekskyworld]

Problem

Issue #132 tracks removal of the published background inverse alias from the Workflow launch API. The compatibility window has ended for the 1.0.0 breaking release, but the model-facing schema and coordinator still accepted both wait and background.

Value

A single positive wait policy reduces schema ambiguity and prevents conflicting inverse booleans from reaching the Workflow runtime. Existing persisted workflow artifacts and operator-facing detached-state facts remain readable.

Approach

• Remove background from the Workflow launch schema and launch-policy input.
• Resolve inline/detached mode from wait and host delivery capability only.
• Remove deprecated alias rendering and prompt copy.
• Keep WorkflowDetails.background and persisted artifact fields unchanged for historical compatibility.
• Update the Workflow reference/design documentation and focused schema/coordinator/rendering/e2e tests.
• Bump the package version from 0.4.0 to 1.0.0 for the breaking API change.

Validation

• npx --yes bun@1.3.14 run lint — passed.
• npx --yes bun@1.3.14 run typecheck — passed.
• npx --yes bun@1.3.14 run test — 1065 passed, 1 skipped; Vitest 30 passed.
• node --test --experimental-strip-types tests/extensions/workflows/coordinator.test.ts tests/extensions/workflows/rendering.test.ts — 15 passed.
• git diff --check — passed.
• npx --yes bun@1.3.14 run check — blocked only by pre-existing formatting differences in untracked .golutra JSON files; those user-owned collaboration files were not modified.

Impact

• User-visible behavior: callers must use wait; background is rejected as an unknown argument.
• Model-visible context/tools: Workflow schema exposes only wait.
• Runtime/lifecycle: inline/detached lifecycle semantics are unchanged.
• Persisted data: WorkflowDetails.background and historical artifact fields remain intact.
• Compatibility/risk: this is intentionally a 1.0.0 breaking change; released callers using background must migrate to wait.

Fixes #132

[tt-a1i]

Reviewed exact head 5dcb67522e9e88c54a50e40b717ca5a1101b1cac.

Problem / Value / Approach

统一到正向的 wait，删除相反布尔值及兼容分支，方向合理。schema 保持 additionalProperties: false，旧参数由 Pi 原生校验拒绝；WorkflowDetails/artifact 的 background 继续记录实际运行状态。未发现新增运行时缺陷或需要额外设计的地方。

Standards

[P2] 请保留 #139 的历史结论与验证，不要原地改成 #305 的新行为。设计文档 671–677 已改为删除 alias，却仍把最终验证归给 #139 exact-head review；#139 实际验证的是接受 deprecated alias。按 docs/README.md 的历史结论只追加规则，保留原段落，另加本次变更说明、revision 与验证边界即可。

Spec

1. 迁移/发布前提还需要维护者明确。这是兼容门槛，不是已证实的 runtime bug。Issue #132 与 #139 最终合并合同要求先给迁移提示、在另行公告的 breaking release 删除。当前 GitHub latest v0.4.0 发布于 2026-08-24，早于 #139 在 2026-08-30 合入；仅把 package.json 改成 1.0.0，不能证明 PR 所称“兼容窗口已结束”。请关联明确的 breaking 发布安排，并保留可操作的映射：background:true → wait:false；background:false → wait:true。若维护者决定直接 breaking，应明确记录这个决定，不必为此新造兼容框架。
2. 本轴也发现上面的 #139 验证错引。
   删除目标本身实现正确：wait/host capability、cancellation 与历史 artifact 兼容边界未见回归。

Verification

在该 exact head 的隔离工作树验证：

• bun run check passed；
• bun run test：Node 1065 passed / 1 skipped，Vitest 30 passed；
• focused coordinator/rendering：15/15；
• git diff --check passed。
  现有 CI 通过，但分支 behind main；同步后需要最终 head 的新检查。本 review 不代表 runtime smoke、合并或 release 验收。

结论：Changes requested。收口历史文档和 breaking 发布前提后可复审；本轮未修改代码、未合并。

[tt-a1i]

⚠️ [P2] 这里把本次删除 alias 写进了 #139 的历史合同，而下面 675–677 仍把最终验证归于 #139 exact-head review；那个 review 实际验证的是保留 alias。请保留 #139 原结论和对应凭证，另追加 #305 的变更说明与本次验证边界，避免旧凭证证明相反的新行为。

[tt-a1i]

Code Review Summary

Changes requested，固定 head 5dcb675。正式 review。

• 删除反向 alias 的实现方向合理，未发现新增运行时缺陷；本地 check、全量测试和专项测试通过。
• 请保留 fix(workflows): deprecate background launch alias #139 历史记录，另加 fix(workflows): remove background launch alias #305 的变更与验证说明，不复用旧 review 证明相反的新行为。
• 需要维护者明确 1.0.0 breaking 发布与迁移安排；这是兼容门槛，不要求再造框架。
• 分支 behind main，同步后需要新 head 检查。本轮未修改、推送或合并。