feat: add stopFailure and postCompact (#2825)

docs/users/features/hooks.md

@@ -57,9 +57,11 @@ The following table lists all available hook events in Qwen Code:
 | `UserPromptSubmit`   | Fired when user submits a prompt            | Input processing, validation, context injection |
 | `SessionStart`       | Fired when a new session starts             | Initialization, context setup                   |
 | `Stop`               | Fired before Qwen concludes its response    | Finalization, cleanup                           |
+| `StopFailure`        | Fired when turn ends due to API error       | Error logging, alerting, rate limit handling    |
 | `SubagentStart`      | Fired when a subagent starts                | Subagent initialization                         |
 | `SubagentStop`       | Fired when a subagent stops                 | Subagent finalization                           |
 | `PreCompact`         | Fired before conversation compaction        | Pre-compaction processing                       |
+| `PostCompact`        | Fired after conversation compaction         | Summary archiving, usage statistics             |
 | `SessionEnd`         | Fired when a session ends                   | Cleanup, reporting                              |
 | `PermissionRequest`  | Fired when permission dialogs are displayed | Permission automation, policy enforcement       |
 
@@ -299,6 +301,60 @@ Event-specific fields are added based on the hook type. Below are the event-spec
 }
 ```
 
+#### StopFailure
+
+**Purpose**: Executed when the turn ends due to an API error (instead of Stop). This is a **fire-and-forget** event - hook output and exit codes are ignored.
+
+**Event-specific fields**:
+
+```json
+{
+  "error": "rate_limit | authentication_failed | billing_error | invalid_request | server_error | max_output_tokens | unknown",
+  "error_details": "detailed error message (optional)",
+  "last_assistant_message": "the last message from the assistant before the error (optional)"
+}
+```
+
+**Matcher**: Matches against the `error` field. For example, `"matcher": "rate_limit"` will only trigger for rate limit errors.
+
+**Output Options**:
+
+- **None** - StopFailure is fire-and-forget. All hook output and exit codes are ignored.
+
+**Exit Code Handling**:
+
+| Exit Code | Behavior                  |
+| --------- | ------------------------- |
+| Any       | Ignored (fire-and-forget) |
+
+**Example Configuration**:
+
+```json
+{
+  "hooks": {
+    "StopFailure": [
+      {
+        "matcher": "rate_limit",
+        "hooks": [
+          {
+            "type": "command",
+            "command": "/path/to/rate-limit-alert.sh",
+            "name": "rate-limit-alerter"
+          }
+        ]
+      }
+    ]
+  }
+}
+```
+
+**Use Cases**:
+
+- Rate limit monitoring and alerting
+- Authentication failure logging
+- Billing error notifications
+- Error statistics collection
+
 #### SubagentStart
 
 **Purpose**: Executed when a subagent (like the Task tool) is started to set up context or permissions.
@@ -387,6 +443,63 @@ Event-specific fields are added based on the hook type. Below are the event-spec
 }
 ```
 
+#### PostCompact
+
+**Purpose**: Executed after conversation compaction completes to archive summaries or track usage.
+
+**Event-specific fields**:
+
+```json
+{
+  "trigger": "manual | auto",
+  "compact_summary": "the summary generated by the compaction process"
+}
+```
+
+**Matcher**: Matches against the `trigger` field. For example, `"matcher": "manual"` will only trigger for manual compaction via `/compact` command.
+
+**Output Options**:
+
+- `hookSpecificOutput.additionalContext`: additional context (for logging only)
+- Standard hook output fields (for logging only)
+
+**Note**: PostCompact is **not** in the official decision mode supported events list. The `decision` field and other control fields do not produce any control effects - they are only used for logging purposes.
+
+**Exit Code Handling**:
+
+| Exit Code | Behavior                                                  |
+| --------- | --------------------------------------------------------- |
+| 0         | Success - stdout shown to user in verbose mode            |
+| Other     | Non-blocking error - stderr shown to user in verbose mode |
+
+**Example Configuration**:
+
+```json
+{
+  "hooks": {
+    "PostCompact": [
+      {
+        "matcher": "manual",
+        "hooks": [
+          {
+            "type": "command",
+            "command": "/path/to/save-compact-summary.sh",
+            "name": "save-summary"
+          }
+        ]
+      }
+    ]
+  }
+}
+```
+
+**Use Cases**:
+
+- Summary archiving to files or databases
+- Usage statistics tracking
+- Context change monitoring
+- Audit logging for compaction operations
+
 #### Notification
 
 **Purpose**: Executed when notifications are sent to customize or intercept them.