Merge remote-tracking branch 'origin/worktree-process-service-seam' into subprocess-simpl/d-one-env-channel

# Conflicts:
#	docs/cordis-catalog/services.md
#	docs/core-data-structures/subprocess.i18n.yaml
#	packages/lsp/lsp-local/src/connection.ts
#	packages/subagent/subagent-acp/README.i18n.yaml
#	packages/subprocess/subprocess-local/README.i18n.yaml
#	packages/subprocess/subprocess-local/src/spawn.ts
#	packages/subprocess/subprocess/README.i18n.yaml
#	packages/subprocess/subprocess/README.md
#	packages/subprocess/subprocess/README.zh.md
#	packages/subprocess/subprocess/tests/service.spec.ts

packages/lsp/lsp-local/src/connection.ts

@@ -29,11 +29,11 @@ export interface ConnectionSpec {
   /** Largest stderr tail retained for diagnostics. */
   readonly maxStderrBytes: number
   /**
-   * Bound (ms) for draining pipes a surviving helper still holds after the
-   * server exits; the instance passes its kill grace so exit observation is
-   * never slower than the escalation it feeds.
+   * The subprocess spec's `graceMs`: the SIGTERM→SIGKILL window of
+   * {@link LspConnection.terminate}'s escalation, and the bound for draining
+   * pipes a surviving helper still holds after the server exits.
    */
-  readonly pipeDrainGraceMs: number
+  readonly killGraceMs: number
   /** Static answer to every `workspace/configuration` item. */
   readonly configuration: unknown
 }
@@ -97,7 +97,7 @@ export class LspConnection {
         stdout: 'pipe',
         stderr: { maxBytes: spec.maxStderrBytes },
       },
-      graceMs: spec.pipeDrainGraceMs,
+      graceMs: spec.killGraceMs,
       // spec.env mixes the scrubbed base with explicit config entries; the
       // seam merges the whole map after its own ambient scrub, so a
       // configured DSH_* fact reaches the child.
@@ -210,14 +210,9 @@ export class LspConnection {
     return this.nextId
   }
 
-  /** Request termination of the server's process tree (SIGTERM, no escalation). */
+  /** Terminate the server's process tree (the seam's SIGTERM→grace→SIGKILL escalation; idempotent). */
   terminate(): void {
-    this.handle.kill('SIGTERM')
-  }
-
-  /** Force termination of the server's process tree. */
-  kill(): void {
-    this.handle.kill('SIGKILL')
+    this.handle.terminate()
   }
 
   /**
@@ -235,9 +230,10 @@ export class LspConnection {
       messages = this.decoder.push(chunk)
     } catch (error) {
       // A framing/JSON failure corrupts the stream position irrecoverably: fail the instance and
-      // SIGKILL the whole group so helper processes don't outlive the leader.
+      // terminate the whole group so helper processes don't outlive the leader (SIGTERM first, then
+      // the kill grace's SIGKILL — a misbehaving server still gets its bounded flush window).
       this.fail(asError(error))
-      this.handle.kill('SIGKILL')
+      this.handle.terminate()
       return
     }
     for (const message of messages) this.dispatch(message)

packages/lsp/lsp-local/src/index.ts

@@ -285,8 +285,6 @@ class LocalLspProvider implements LspProvider {
       initializationOptions: this.config.initializationOptions,
       maxMessageBytes: this.config.maxMessageBytes,
       maxStderrBytes: this.config.maxStderrBytes,
-      // Exit observation must never be slower than the escalation it feeds.
-      pipeDrainGraceMs: this.config.killGraceMs,
       shutdownTimeoutMs: this.config.shutdownTimeoutMs,
       killGraceMs: this.config.killGraceMs,
     }

packages/lsp/lsp-local/src/instance.ts

@@ -35,17 +35,6 @@ export interface InstanceSpec extends ConnectionSpec {
   readonly initializationOptions: unknown
   /** Graceful `shutdown`/`exit` budget before escalation (ms). */
   readonly shutdownTimeoutMs: number
-  /** SIGTERM→SIGKILL grace after graceful shutdown fails (ms). */
-  readonly killGraceMs: number
-}
-
-/**
- * Force-kill a process tree only when graceful termination did not make it exit.
- * @param treeExited - whether the tree exited within its grace period.
- * @param forceKill - forceful process-tree termination primitive.
- */
-export function escalateProcessTree(treeExited: boolean, forceKill: () => void): void {
-  if (!treeExited) forceKill()
 }
 
 /**
@@ -311,17 +300,14 @@ export class LspInstance {
     await abortable(this.connection.closed, signal)
   }
 
-  /** Terminate the tree, escalate after `killGraceMs`, then await leader and helper exit. */
+  /**
+   * Terminate the tree (the seam escalates SIGTERM→`killGraceMs`→SIGKILL),
+   * then await leader and helper exit. The awaits are unbounded on purpose:
+   * the seam's escalation already committed to SIGKILL, so quiescence — not
+   * another timer — is the postcondition disposal owes its callers.
+   */
   private async forceTerminate(): Promise<void> {
     this.connection.terminate()
-    const graceDeadline = deadline(undefined, this.spec.killGraceMs, 'LSP_KILL_GRACE')
-    let treeExited: boolean
-    try {
-      treeExited = await this.connection.waitForProcessTreeExit(graceDeadline.signal)
-    } finally {
-      graceDeadline[Symbol.dispose]()
-    }
-    escalateProcessTree(treeExited, this.connection.kill.bind(this.connection))
     await Promise.all([
       this.connection.closed,
       this.connection.waitForProcessTreeExit(),