docs(tasks): condense background task prose

The background-task change repeated its lifecycle design across implemented RFCs, package READMEs, JSDoc, test commentary, and model-visible schemas. That repetition obscured the contracts that maintainers must preserve and added avoidable prompt tokens.

Rewrite the implemented RFCs around the current design, keep authorization, exact-owner cleanup, wait/abort ordering, producer quiescence, and teardown-failure guarantees at their owning surfaces, and remove peer surveys, review history, control-flow narration, and emphatic restatement.

Shorten the task and subagent schema wording, synchronize the bilingual tool cookbook, and regenerate the config, service, RFC, tool, and replay snapshot derivatives. Runtime behavior is unchanged; test edits update prose-only assertions and descriptions.

packages/bash/bash-sandbox/src/index.ts

@@ -20,7 +20,7 @@ import type { Config as LocalConfig } from '@deepseek-ai/dsh-bash-local'
  * Plugin config: the local executor's knobs plus the sandbox policy. All
  * optional — `static Config` supplies the defaults (`mode: 'read-only'` is the
  * fail-safe default; an example that wants a workspace-writable agent opts in
- * explicitly). The runner choice is NOT configured here: which platform
+ * explicitly). The runner choice is not configured here: which platform
  * backend confines the command is the `ctx.sandbox` provider's config.
  */
 export interface Config extends LocalConfig {
@@ -70,10 +70,8 @@ export function classifyRunnerFailure(result: BashRunResult, signatures: readonl
 }
 
 /**
- * The classifier core shared by foreground results and settled background
- * tasks: failed AND signature present. Lowercases BOTH sides — the seam
- * declares its signatures case-insensitive, and producers compose them from
- * runtime data of any case (an `argv0` path, `No such file or directory`).
+ * Shared classifier for failed runs. Signatures are case-insensitive and may
+ * include runtime values such as an executable path.
  */
 function matchesSignature(exitCode: number | null, stderr: string, signatures: readonly string[]): boolean {
   if (exitCode === null || exitCode === 0) return false
@@ -104,15 +102,10 @@ export class SandboxBashExecutor extends LocalBashExecutor {
   private readonly mode: SandboxMode
   private readonly workspaceRoot: string
   /**
-   * Per-process facts, keyed by handle from `start()` until the settle stamp
-   * consumes them: the mode the process runs under (per-call — an escalated process
-   * differs from its neighbors) plus its wrap facts. The seam returns facts
-   * PER WRAP — a provider may legally vary enforcement or dialect between
-   * calls — so overlapping background processes must each classify against their
-   * OWN wrap; a single latest-wrap field would let a later `start()` clobber
-   * an earlier process's facts before it settles. A `danger-full-access` process
-   * has NO entry (nothing confined it), which is what the settle stamp keys
-   * off.
+   * Per-process confinement facts retained until settlement. Providers may
+   * vary enforcement and diagnostic dialect between overlapping calls, so a
+   * shared latest-wrap value would classify a process against the wrong facts.
+   * Unconfined processes have no entry.
    */
   private readonly processFacts = new Map<BashProcess, {
     mode: ConfinedSandboxMode
@@ -123,10 +116,7 @@ export class SandboxBashExecutor extends LocalBashExecutor {
 
   constructor(ctx: Context, config: Config) {
     super(ctx, config)
-    // schemastery (static Config) already filled the defaulted fields — the
-    // cast records that runtime fact (mirrors LocalBashExecutor's config
-    // cast). `workspaceRoot` and `cwd` have NO schema default, so their
-    // fallback chain is real branching.
+    // Schemastery fills mode before construction; workspaceRoot and cwd retain runtime fallbacks.
     this.mode = config.mode as SandboxMode
     this.workspaceRoot = resolve(config.workspaceRoot ?? config.cwd ?? process.cwd())
   }
@@ -168,11 +158,7 @@ export class SandboxBashExecutor extends LocalBashExecutor {
     // Same stamped-by-resolve invariant as run().
     const mode = spec.sandboxMode as SandboxMode
     if (mode === 'danger-full-access') return super.start(spec)
-    // Sandbox facts are stamped at settle time by onProcessDone()
-    // (denial classification runs against the settled task's collected
-    // stderr). The map entry lands synchronously after spawn, strictly
-    // before the earliest possible settle (including a spawn rejection, whose
-    // promise reaction cannot run until this synchronous start call returns).
+    // Install facts synchronously; promise settlement cannot run before start() returns.
     const confined = this.confine(spec.command, mode)
     const proc = super.start({ ...spec, command: confined.command })
     const { enforcement, denialSignatures, runnerFailureSignatures } = confined
@@ -188,10 +174,7 @@ export class SandboxBashExecutor extends LocalBashExecutor {
     const facts = this.processFacts.get(proc)
     if (facts !== undefined) {
       this.processFacts.delete(proc)
-      // Runner failure outranks denial (the command never ran; the runner's
-      // own error text can contain denial words). A settled task has no
-      // error channel left, so the fact IS the surface here — the foreground
-      // path throws instead.
+      // Runner failure outranks denial because its diagnostics may contain denial terms.
       const runnerFailed = matchesSignature(proc.exitCode, stderr, facts.runnerFailureSignatures)
       proc.sandbox = {
         mode: facts.mode,