fix(rebase): migrate the replayed stack onto current master APIs

The linear replay carried each commit's own lineage, so this checkpoint
restores the master-owned surfaces the conflicted regions clobbered and
migrates branch-owned code to master's post-rebase APIs:

- rebuild subprocess-local spawn.ts on master's tree-exit-observer
  machinery, keeping the branch's win32 childEnv key semantics and the
  Linux zombie-quiescence probe; the zombie test reaps its survivor
  directly since a confirmed-absent verdict is a permanent
  no-more-signals boundary
- migrate pty-local test stubs to the Inbox-model Agent interface,
  Session.create, runnerFailureRules, and the new turn/start payload
- implement the seam's resolveExecutable/spawnTerminal abstracts in the
  new pwsh-local and tool-fs-search test fakes
- restore code-runtime, atomic-write, pwsh-local, and app-boot to
  master's exact content (the net-zero code-runtime churn is pruned
  from this history) and drop rename-detection graft debris
- re-apply the PR's architecture rows and execution-world paragraph,
  re-record bilingual pairings, regenerate catalogs, and reconcile the
  lockfile

pnpm-lock.yaml

@@ -4275,6 +4275,12 @@ importers:
       '@deepseek-ai/dsh-brand':
         specifier: workspace:^
         version: link:../../util/brand
+      '@deepseek-ai/dsh-fs':
+        specifier: workspace:^
+        version: link:../../fs/fs
+      '@deepseek-ai/dsh-fs-local':
+        specifier: workspace:^
+        version: link:../../fs/fs-local
       '@deepseek-ai/dsh-invariants':
         specifier: workspace:^
         version: link:../../support/invariants
@@ -4312,6 +4318,9 @@ importers:
       '@deepseek-ai/dsh-agent':
         specifier: workspace:^
         version: link:../../core/agent
+      '@deepseek-ai/dsh-fs-local':
+        specifier: workspace:^
+        version: link:../../fs/fs-local
       '@deepseek-ai/dsh-invariants':
         specifier: workspace:^
         version: link:../../support/invariants
@@ -4327,6 +4336,9 @@ importers:
       '@deepseek-ai/dsh-session':
         specifier: workspace:^
         version: link:../../core/session
+      '@deepseek-ai/dsh-subprocess-local':
+        specifier: workspace:^
+        version: link:../../subprocess/subprocess-local
       '@deepseek-ai/dsh-system-prompt':
         specifier: workspace:^
         version: link:../../core/system-prompt
@@ -4440,9 +4452,6 @@ importers:
 
   packages/pty/pty-local:
     dependencies:
-      node-pty:
-        specifier: ^1.1.0
-        version: 1.1.0(patch_hash=7a0c04f1f49d798a9ffe2f7f414c01064a44ca2489772d0c3e1235ab336755e6)
       schemastery:
         specifier: ^3.18.0
         version: link:../../../vendor/schemastery
@@ -4468,6 +4477,9 @@ importers:
       '@deepseek-ai/dsh-subprocess':
         specifier: workspace:^
         version: link:../../subprocess/subprocess
+      '@deepseek-ai/dsh-subprocess-local':
+        specifier: workspace:^
+        version: link:../../subprocess/subprocess-local
       cordis:
         specifier: ^4.0.0-rc.7
         version: link:../../../vendor/cordis
@@ -4563,6 +4575,9 @@ importers:
       '@deepseek-ai/dsh-session':
         specifier: workspace:^
         version: link:../../core/session
+      '@deepseek-ai/dsh-subprocess-local':
+        specifier: workspace:^
+        version: link:../../subprocess/subprocess-local
       '@deepseek-ai/dsh-system-prompt':
         specifier: workspace:^
         version: link:../../core/system-prompt
@@ -5940,6 +5955,10 @@ importers:
         version: link:../../../vendor/cordis
 
   packages/subprocess/subprocess-local:
+    dependencies:
+      node-pty:
+        specifier: ^1.1.0
+        version: 1.1.0(patch_hash=7a0c04f1f49d798a9ffe2f7f414c01064a44ca2489772d0c3e1235ab336755e6)
     devDependencies:
       '@deepseek-ai/dsh-invariants':
         specifier: workspace:^