feat: v0.4.1 — ChatGPT tool-output content types and conv_id fix

First real-data export against v0.4.0 surfaced 66 unknown blocks across
three content types — captured live and added.

Added:
- execution_output (Code Interpreter / container.exec / python tool
  output) → tool_result block. output=content.text,
  tool_name=author.name, is_error=metadata.aggregate_result.status,
  summary=metadata.reasoning_title
- system_error → error tool_result with tool_name=author.name
- tether_browsing_display: spinner placeholders (empty result+summary)
  skip silently with DEBUG log; defensive populated-case branch maps
  to tool_result (untested in real data)
- tool_result block schema: optional `summary` field rendered as
  italic line between header and fence
- tool_result rendering: tool_name appears in header when present
  (e.g. `📤 Result: container.exec`); existing tool_name=None calls
  unchanged
- _ROLE_LABELS["tool"] = ("🔧 Tool", "tool")

Fixed:
- chatgpt.normalize_conversation reads `conversation_id` as fallback
  for `id`. Live API uses conversation_id; fixtures use id.
  Pre-fix: empty id in YAML frontmatter and missing context in
  WARNING logs.

Tests: 11 new (192 total, 0 failures). Fixture extended with 4
tool-output cases (execution_output success, empty execution_output
that should skip, system_error, tether_browsing_display spinner).

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

CHANGELOG.md

@@ -3,6 +3,22 @@
 All notable changes to this project will be documented here.
 Format follows [Keep a Changelog](https://keepachangelog.com/en/1.0.0/).
 
+## [0.4.1] - Unreleased
+### Added
+- ChatGPT `execution_output` (Code Interpreter / `container.exec` / `python`) renders as a `tool_result` block with `tool_name` from `author.name`, `is_error` from `metadata.aggregate_result.status`, and the optional `summary` line populated from `metadata.reasoning_title`. Captured live during planning.
+- ChatGPT `system_error` content (e.g. browse-service 503) renders as an error `tool_result` block with `tool_name` from `author.name` (typically `"web"`).
+- ChatGPT `tether_browsing_display` populated case (defensive, not observed in real data) renders as a `tool_result` block; transient spinner placeholders (empty `result`+`summary`) skip silently with DEBUG log.
+- `tool_result` block schema gains optional `summary: str | None` field, rendered as italic line between header and fenced output.
+- `tool_result` rendering shows `tool_name` in the header when present (e.g. `📤 **Result: container.exec**`); when absent, header stays as `📤 **Result**` (no regression).
+- Markdown exporter: `_ROLE_LABELS["tool"] = ("🔧 Tool", "tool")` so tool-role messages render under a recognisable header instead of the generic fallback.
+- 11 new tests covering all four cases plus the conv_id fallback (192 total, all passing).
+
+### Fixed
+- ChatGPT `normalize_conversation` now reads `conversation_id` as a fallback for `id`. Live ChatGPT detail responses use `conversation_id` at top level; fixtures and listing summaries use `id`. Without the fallback, normalized conversations had empty `id` (visible as blank `conversation_id:` in YAML frontmatter and missing context in WARNING log lines).
+
+### Migration
+- No new schema breaks; `tool_result` blocks gain a `summary` field that defaults to None on legacy data. Existing exports re-render cleanly with the cache-clear-and-export workflow from v0.4.0.
+
 ## [0.4.0] - Unreleased
 ### Added
 - Rich content support: messages now carry an ordered `blocks` list (text, code, thinking, tool_use, tool_result, citation, image_placeholder, file_placeholder, unknown)