[codex] fix bridge tool marker flush persistence (#1002)

* fix: don't drop pending tool-call-marker prefix on tool.started/run.done

The `filterBridgeToolCallMarkupDelta` filter holds back any text that
ends in a partial prefix of `[Calling tool:` (i.e. `[`, `[C`, `[Ca`,
..., `[Calling tool`) so it can decide whether the buffered chars are
the start of a tool-call markup block to be hidden, or just regular
text to be released by the next delta.

The bug: that "release on next delta" assumption breaks at TWO points:

1. **On `tool.started`**: the next chunk for this assistant message is
   the tool call itself, NOT a follow-up text delta. Buffered chars
   sit there forever and nothing flushes them — they vanish silently
   from the user-visible stream.

2. **On run completion**: the code did
   `state.bridgePendingToolCallMarkup = undefined` directly, dropping
   any pending chars without forwarding them.

Both cases produce the user-visible symptom of "abrupt cuts in text
right before/after tool calls (terminal, read_file, write_file...)" —
1 to 13 characters disappear at exactly the boundary where the model
was emitting natural prose that happened to end with `[`.

The fix introduces `flushPendingToolCallMarkup(state)` and calls it:

- In the `tool.started` branch BEFORE recording the tool call, so the
  buffered chars are appended to the open assistant message and emitted
  as a normal `message.delta` to the client.
- At run-done BEFORE clearing the buffer, same flush path.

This is a pure recovery patch — no change to the marker detection
logic itself. If the buffer turns out to actually be a real
`[Calling tool: ...]` marker that just hasn't completed yet, that
case is still caught by the existing `markerIdx >= 0` branch in the
filter on the next delta. The only behavioral change is that the
"orphan" cases (text that ends with `[` but never becomes a marker)
are no longer dropped.

* fix bridge marker flush persistence

---------

Co-authored-by: Paulo Cavallari <paulocavallari@users.noreply.github.com>

tests/server/run-chat-bridge-delta.test.ts

@@ -1,6 +1,6 @@
 import { describe, expect, it } from 'vitest'
 
-import { filterBridgeToolCallMarkupDelta } from '../../packages/server/src/services/hermes/run-chat/bridge-delta'
+import { filterBridgeToolCallMarkupDelta, flushPendingToolCallMarkup } from '../../packages/server/src/services/hermes/run-chat/bridge-delta'
 
 describe('run-chat bridge delta filtering', () => {
   it('keeps ordinary assistant text', () => {
@@ -37,4 +37,12 @@ describe('run-chat bridge delta filtering', () => {
     expect(filterBridgeToolCallMarkupDelta(state, 'Text [Call')).toBe('Text ')
     expect(filterBridgeToolCallMarkupDelta(state, 'ing tool: terminal with arguments: {}]\nDone')).toBe('Done')
   })
+
+  it('flushes an orphan partial marker suffix when no text chunk follows', () => {
+    const state = {}
+
+    expect(filterBridgeToolCallMarkupDelta(state, 'Text [Call')).toBe('Text ')
+    expect(flushPendingToolCallMarkup(state)).toBe('[Call')
+    expect(flushPendingToolCallMarkup(state)).toBe('')
+  })
 })