Merge origin/master (generic task runtime #219, single-exe closure, package renames)

Semantic resolutions beyond line merges:
- The bash seam keeps resolveMode + the bash/resolve-mode waterfall on
  master's task-free BashExecutor (run/start/resolve only; BashProcess
  handles); tool-bash consults it at its stamping site and escalation
  baseline on master's render/background split, with a waterfall test on
  the recording executor.
- dsh-mode's BASH_FAMILY narrows to ['bash']: bash_output/bash_kill are
  replaced by the kind-generic task_output/task_kill, which span every
  task kind and only observe or stop work, so the access cap withholds
  only the starter it can reason about.
- The plan-mode snapshot suite adopts master's pin grammar (tool-schema
  sidecars; the expectedHeaderSnapshots extension is gone — the exit
  transition deltas, and entering-before-turn-1 needs no second
  snapshot); modes-advertise joins the plan header class (no-model, so
  membership is vacuous). Fixtures re-recorded on the acp-demo bin;
  the replay overlay gains the passthrough sandbox runner.
- examples/plan-acp-agent rewires to @deepseek-ai/dsh-acp-demo and drops
  its tool-bash entry (the spine bundle now composes it); dsh-stdio (the
  renamed stdio-chat home) keeps its /mode command and gains the dsh-mode
  peer edge; the acp bridge keeps the modes surface beside master's
  permission presets.
- mode README gains the Model Experience / Known Limitations sections the
  new README gates require; AGENTS.md ceiling 1370 → 1440 for the kept
  mode/ layout line and Agent efficiency section.

tsconfig.base.json

@@ -47,9 +47,11 @@
         "./packages/fs/*/src",
         "./packages/skill/*/src",
         "./packages/compact/*/src",
+        "./packages/context/*/src",
         "./packages/guard/*/src",
         "./packages/mode/*/src",
         "./packages/subagent/*/src",
+        "./packages/tasks/*/src",
         "./packages/workflow/*/src",
         "./packages/web/*/src",
         "./packages/timeout/*/src",
@@ -58,8 +60,11 @@
         "./packages/sandbox/*/src",
         "./packages/hooks/*/src",
         "./packages/session-persistence/*/src",
+        "./packages/session-query/*/src",
         "./packages/ui/*/src",
+        "./packages/examples/*/src",
         "./packages/util/*/src",
+        "./packages/mcp/*/src",
         "./packages/support/*/src"
       ]
     }