fix(streaming): prevent <think> in prose from suppressing response output

When the model mentions <think> as literal text in its response (e.g.
"(/think not producing <think> tags)"), the streaming display treated it
as a reasoning block opener and suppressed everything after it. The
response box would close with truncated content and no error — the API
response was complete but the display ate it.

Root cause: _stream_delta() matched <think> anywhere in the text stream
regardless of position. Real reasoning blocks always start at the
beginning of a line; mentions in prose appear mid-sentence.

Fix: track line position across streaming deltas with a
_stream_last_was_newline flag. Only enter reasoning suppression when
the tag appears at a block boundary (start of stream, after a newline,
or after only whitespace on the current line). Add a _flush_stream()
safety net that recovers buffered content if no closing tag is found
by end-of-stream.

Also fixes three related issues discovered during investigation:

- anthropic_adapter: _get_anthropic_max_output() now normalizes dots to
  hyphens so 'claude-opus-4.6' matches the 'claude-opus-4-6' table key
  (was returning 32K instead of 128K)

- run_agent: send explicit max_tokens for Claude models on Nous Portal,
  same as OpenRouter — both proxy to Anthropic's API which requires it.
  Without it the backend defaults to a low limit that truncates responses.

- run_agent: reset truncated_tool_call_retries after successful tool
  execution so a single truncation doesn't poison the entire conversation.

tests/cli/test_stream_delta_think_tag.py

@@ -0,0 +1,138 @@
+"""Tests for _stream_delta's handling of <think> tags in prose vs real reasoning blocks."""
+import sys
+import os
+sys.path.insert(0, os.path.join(os.path.dirname(__file__), "..", ".."))
+
+import pytest
+
+
+def _make_cli_stub():
+    """Create a minimal HermesCLI-like object with stream state."""
+    from cli import HermesCLI
+
+    cli = HermesCLI.__new__(HermesCLI)
+    cli.show_reasoning = False
+    cli._stream_buf = ""
+    cli._stream_started = False
+    cli._stream_box_opened = False
+    cli._stream_prefilt = ""
+    cli._in_reasoning_block = False
+    cli._reasoning_stream_started = False
+    cli._reasoning_box_opened = False
+    cli._reasoning_buf = ""
+    cli._reasoning_preview_buf = ""
+    cli._deferred_content = ""
+    cli._stream_text_ansi = ""
+    cli._stream_needs_break = False
+    cli._emitted = []
+
+    # Mock _emit_stream_text to capture output
+    def mock_emit(text):
+        cli._emitted.append(text)
+    cli._emit_stream_text = mock_emit
+
+    # Mock _stream_reasoning_delta
+    cli._reasoning_emitted = []
+    def mock_reasoning(text):
+        cli._reasoning_emitted.append(text)
+    cli._stream_reasoning_delta = mock_reasoning
+
+    return cli
+
+
+class TestThinkTagInProse:
+    """<think> mentioned in prose should NOT trigger reasoning suppression."""
+
+    def test_think_tag_mid_sentence(self):
+        """'(/think not producing <think> tags)' should pass through."""
+        cli = _make_cli_stub()
+        tokens = [
+            "  1. Fix reasoning mode in eval ",
+            "(/think not producing ",
+            "<think>",
+            " tags — ~2% gap)",
+            "\n  2. Launch production",
+        ]
+        for t in tokens:
+            cli._stream_delta(t)
+        assert not cli._in_reasoning_block, "<think> in prose should not enter reasoning block"
+        full = "".join(cli._emitted)
+        assert "<think>" in full, "The literal <think> tag should be in the emitted text"
+        assert "Launch production" in full
+
+    def test_think_tag_after_text_on_same_line(self):
+        """'some text <think>' should NOT trigger reasoning."""
+        cli = _make_cli_stub()
+        cli._stream_delta("Here is the <think> tag explanation")
+        assert not cli._in_reasoning_block
+        full = "".join(cli._emitted)
+        assert "<think>" in full
+
+    def test_think_tag_in_backticks(self):
+        """'`<think>`' should NOT trigger reasoning."""
+        cli = _make_cli_stub()
+        cli._stream_delta("Use the `<think>` tag for reasoning")
+        assert not cli._in_reasoning_block
+
+
+class TestRealReasoningBlock:
+    """Real <think> tags at block boundaries should still be caught."""
+
+    def test_think_at_start_of_stream(self):
+        """'<think>reasoning</think>answer' should suppress reasoning."""
+        cli = _make_cli_stub()
+        cli._stream_delta("<think>")
+        assert cli._in_reasoning_block
+        cli._stream_delta("I need to analyze this")
+        cli._stream_delta("</think>")
+        assert not cli._in_reasoning_block
+        cli._stream_delta("Here is my answer")
+        full = "".join(cli._emitted)
+        assert "Here is my answer" in full
+        assert "I need to analyze" not in full  # reasoning was suppressed
+
+    def test_think_after_newline(self):
+        """'text\\n<think>' should trigger reasoning block."""
+        cli = _make_cli_stub()
+        cli._stream_delta("Some preamble\n<think>")
+        assert cli._in_reasoning_block
+        full = "".join(cli._emitted)
+        assert "Some preamble" in full
+
+    def test_think_after_newline_with_whitespace(self):
+        """'text\\n  <think>' should trigger reasoning block."""
+        cli = _make_cli_stub()
+        cli._stream_delta("Some preamble\n  <think>")
+        assert cli._in_reasoning_block
+
+    def test_think_with_only_whitespace_before(self):
+        """'   <think>' (whitespace only prefix) should trigger."""
+        cli = _make_cli_stub()
+        cli._stream_delta("   <think>")
+        assert cli._in_reasoning_block
+
+
+class TestFlushRecovery:
+    """_flush_stream should recover content from false-positive reasoning blocks."""
+
+    def test_flush_recovers_buffered_content(self):
+        """If somehow in reasoning block at flush, content is recovered."""
+        cli = _make_cli_stub()
+        # Manually set up a false-positive state
+        cli._in_reasoning_block = True
+        cli._stream_prefilt = " tags — ~2% gap)\n  2. Launch production"
+        cli._stream_box_opened = True
+
+        # Mock _close_reasoning_box and box closing
+        cli._close_reasoning_box = lambda: None
+
+        # Call flush
+        from unittest.mock import patch
+        import shutil
+        with patch.object(shutil, "get_terminal_size", return_value=os.terminal_size((80, 24))):
+            with patch("cli._cprint"):
+                cli._flush_stream()
+
+        assert not cli._in_reasoning_block
+        full = "".join(cli._emitted)
+        assert "Launch production" in full