test(snapshot): reconcile replay overlays with the merged configs and fixtures

- acp/headless whole-config snapshot patches restate persistenceCompression:
  none so raw JSONL fixtures stay harvestable, and re-pin the recorded
  deepseek-v4-flash where the shipped config moved to pro
- depth-two overlay gains the app-config re-pin master's other overlays carry
- headless-agent stays on flash: goal/ralph overlays include it via a nested
  include, which a config patch cannot reach to re-pin
- workspace-context scenarios re-record their session fixtures for the
  per-candidate scope keys and both-siblings loading; acp session fixtures
  otherwise return to master's (session/title + delegationDepth events)

examples/tui-agent/tests/snapshots/dynamic-workflow/terminal.expected.txt

@@ -1,13 +1,13 @@
 terminal 100x36 buffer=normal length=45 base=9 viewport=9
 lifecycle started=1 stopped=0 progress=inactive
-title "DSH TUI snapshot"
+title "Use the workflow tool exactly — DSH TUI snapshot"
 cursor hidden column=1 viewportRow=33 bufferRow=42
 buffer
 0| " DEEPSEEK HARNESS"
   style 1-8 fg=bright-blue bold
   style 10-16 bold
-1| " Recorded replay: dynamic-workflow"
-  style 1-33 fg=bright-black
+1| " Use the workflow tool exactly"
+  style 1-29 fg=bright-black
 2| " deepseek-v4-flash  •  main-session"
   style 1-34 dim
 3| <blank>
@@ -91,6 +91,6 @@ buffer
   style 1-1 inverse
 43| "────────────────────────────────────────────────────────────────────────────────────────────────────"
   style 0-99 dim
-44| "deepseek-v4-flash  /workspace/project  ↑3.5k ↓227  cache 47%  tools:colla"
+44| "deepseek-v4-flash  /workspace/project  ↑3.5k ↓227  cache 47%  3% context "
   style 0-86 dim
   style 89-99 dim