fix(opencode): handle Nm Ns duration format and extend extraction buffer

Two status/extraction bugs revealed by e2e runs with full system prompts:

1. COMPLETION_MARKER_PATTERN now matches the Nm Ns duration format that
   OpenCode emits for responses that take more than 60 seconds (e.g.
   "1m 8s"). The old pattern only matched the pure-seconds form, causing
   get_status() to stall at PROCESSING indefinitely for longer turns.

2. Add extraction_tail_lines property to BaseProvider (default None) and
   override to 2000 in OpenCodeCliProvider. terminal_service.get_output
   uses this value for the LAST-mode tmux capture so long responses don't
   push the user-message marker (┃  ) beyond the 200-line default window.
   Status-check captures are unaffected.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

Author: patricka3125

src/cli_agent_orchestrator/providers/base.py

@@ -128,6 +128,18 @@ def extraction_retries(self) -> int:
         """
         return 0
 
+    @property
+    def extraction_tail_lines(self) -> Optional[int]:
+        """Number of scrollback lines to capture for output extraction.
+
+        Output extraction needs more history than status detection (which only
+        needs the last few lines for footer/marker checks).  Override in
+        providers whose agents produce long responses that may push the
+        user-message marker beyond ``TMUX_HISTORY_LINES``.  ``None`` uses
+        the default ``TMUX_HISTORY_LINES`` constant.
+        """
+        return None
+
     @abstractmethod
     def extract_last_message_from_script(self, script_output: str) -> str:
         """Extract the last message from terminal script output.

src/cli_agent_orchestrator/providers/opencode_cli.py

@@ -40,9 +40,11 @@
 # User message indent: blue vertical bar + 2 spaces
 USER_MESSAGE_PATTERN = r"^┃\s{2}"
 
-# Per-turn completion marker: "▣  <agent>  ·  <model>  ·  <duration>s"
+# Per-turn completion marker: "▣  <agent>  ·  <model>  ·  <duration>"
 # Two middle-dot separators and a trailing duration are required.
-COMPLETION_MARKER_PATTERN = r"▣\s+\S+\s+·\s+.+?\s+·\s+\d+(?:\.\d+)?s"
+# OpenCode formats duration as "Ns" for short runs and "Nm Ns" once the turn
+# exceeds 60 seconds (e.g. "1m 8s").  Both forms must be matched.
+COMPLETION_MARKER_PATTERN = r"▣\s+\S+\s+·\s+.+?\s+·\s+(?:\d+m\s+)?\d+(?:\.\d+)?s"
 
 # Processing footer — keybind hint present while the agent is generating.
 PROCESSING_FOOTER_PATTERN = r"\besc interrupt\b"
@@ -100,6 +102,18 @@ def paste_enter_count(self) -> int:
         """OpenCode TUI submits on a single Enter after bracketed paste."""
         return 1
 
+    @property
+    def extraction_tail_lines(self) -> int:
+        """Use a larger scrollback window for extraction.
+
+        OpenCode renders the full conversation in the TUI scrollback.  With
+        detailed system prompts, agents can produce responses long enough to
+        push the user-message marker (┃  ) beyond the default 200-line capture
+        window, causing "No user message found" extraction failures.  2000
+        matches the tmux history-limit so we capture the full available buffer.
+        """
+        return 2000
+
     def initialize(self) -> bool:
         """Start the OpenCode TUI and wait for the idle splash frame.
 

src/cli_agent_orchestrator/services/terminal_service.py

@@ -374,6 +374,10 @@ def get_output(terminal_id: str, mode: OutputMode = OutputMode.FULL) -> str:
     retries extraction with 10 s delays between attempts.  This handles
     TUI-based providers (e.g. Gemini CLI's Ink renderer) whose notification
     spinners can temporarily obscure response text in the tmux capture buffer.
+
+    If the provider declares ``extraction_tail_lines``, the history capture
+    for LAST mode uses that value instead of the default ``TMUX_HISTORY_LINES``.
+    Status-check captures are unaffected (they go through get_status directly).
     """
     try:
         metadata = get_terminal_metadata(terminal_id)
@@ -389,14 +393,27 @@ def get_output(terminal_id: str, mode: OutputMode = OutputMode.FULL) -> str:
             if provider is None:
                 raise ValueError(f"Provider not found for terminal {terminal_id}")
 
+            # Re-capture with provider's preferred extraction window if it differs
+            # from the default (status checks use TMUX_HISTORY_LINES; long-response
+            # providers need more lines so user-message markers don't scroll off).
+            extract_lines = provider.extraction_tail_lines
+            if extract_lines is not None:
+                full_output = tmux_client.get_history(
+                    metadata["tmux_session"],
+                    metadata["tmux_window"],
+                    tail_lines=extract_lines,
+                )
+
             retries = provider.extraction_retries
             last_err: Exception | None = None
             for attempt in range(1 + retries):
                 try:
                     if attempt > 0:
                         time.sleep(10.0)
                         full_output = tmux_client.get_history(
-                            metadata["tmux_session"], metadata["tmux_window"]
+                            metadata["tmux_session"],
+                            metadata["tmux_window"],
+                            tail_lines=extract_lines,
                         )
                     return provider.extract_last_message_from_script(full_output)
                 except ValueError as exc:

test/providers/test_opencode_cli_unit.py

@@ -58,6 +58,11 @@ def test_user_message_pattern_rejects_plain_text(self):
     def test_completion_marker_pattern_matches_full_marker(self):
         assert re.search(COMPLETION_MARKER_PATTERN, "▣  Build · Big Pickle · 7.2s")
 
+    def test_completion_marker_pattern_matches_minute_second_duration(self):
+        # Responses > 60 s are formatted as "Nm Ns" by OpenCode.
+        assert re.search(COMPLETION_MARKER_PATTERN, "▣  Data_analyst · Big Pickle · 1m 8s")
+        assert re.search(COMPLETION_MARKER_PATTERN, "▣  Data_analyst · Big Pickle · 2m 30.5s")
+
     def test_completion_marker_pattern_rejects_incomplete(self):
         # No duration suffix → not a full completion marker
         assert not re.search(COMPLETION_MARKER_PATTERN, "▣  Build · Big Pickle")
@@ -386,6 +391,10 @@ def test_get_idle_pattern_for_log_returns_ctrl_p_pattern(self):
     def test_paste_enter_count_is_one(self):
         assert make_provider().paste_enter_count == 1
 
+    def test_extraction_tail_lines_is_2000(self):
+        """extraction_tail_lines must be large enough for long-response agents."""
+        assert make_provider().extraction_tail_lines == 2000
+
 
 # ---------------------------------------------------------------------------
 # Provider manager registration