fix(cli): align session list table for CJK terminal width

Replace str.ljust-based columns with east_asian_width-aware padding so
`hermes sessions list` and inline /history session picks line up when
titles/previews mix Chinese and ASCII. Share one formatter via
print_sessions_table in hermes_cli/main.py.

test(cli): add coverage for display-width helpers in
tests/hermes_cli/test_session_display_width.py.

cli.py

@@ -3990,7 +3990,7 @@ class HermesCLI:
         if not sessions:
             return False
 
-        from hermes_cli.main import _relative_time
+        from hermes_cli.main import print_sessions_table
 
         print()
         if reason == "history":
@@ -3998,13 +3998,7 @@ class HermesCLI:
         else:
             print("  Recent sessions:")
         print()
-        print(f"  {'Title':<32} {'Preview':<40} {'Last Active':<13} {'ID'}")
-        print(f"  {'─' * 32} {'─' * 40} {'─' * 13} {'─' * 24}")
-        for session in sessions:
-            title = (session.get("title") or "—")[:30]
-            preview = (session.get("preview") or "")[:38]
-            last_active = _relative_time(session.get("last_active"))
-            print(f"  {title:<32} {preview:<40} {last_active:<13} {session['id']}")
+        print_sessions_table(sessions, has_titles=True, indent="  ")
         print()
         print("  Use /resume <session id or title> to continue where you left off.")
         print()

hermes_cli/main.py

@@ -173,6 +173,92 @@ from hermes_constants import OPENROUTER_BASE_URL
 logger = logging.getLogger(__name__)
 
 
+def _display_cell_width(ch: str) -> int:
+    """Return terminal column width for a single character (CJK-aware)."""
+    from unicodedata import east_asian_width
+
+    # Fullwidth and wide East Asian — occupy two cells in typical terminals.
+    return 2 if east_asian_width(ch) in ("F", "W") else 1
+
+
+def _text_display_width(s: str) -> int:
+    return sum(_display_cell_width(c) for c in s)
+
+
+def _fit_display_width(s: str, max_cells: int, *, ellipsis: str = "…") -> str:
+    """Truncate ``s`` to at most ``max_cells`` display cells; append ellipsis if truncated."""
+    if _text_display_width(s) <= max_cells:
+        return s
+    ell_w = _text_display_width(ellipsis)
+    if max_cells <= ell_w:
+        return ellipsis[:max_cells] if max_cells > 0 else ""
+    out: list[str] = []
+    w = 0
+    for ch in s:
+        cw = _display_cell_width(ch)
+        if w + cw + ell_w > max_cells:
+            break
+        out.append(ch)
+        w += cw
+    return "".join(out) + ellipsis
+
+
+def _pad_display_right(s: str, width: int) -> str:
+    """Pad ``s`` on the right to exactly ``width`` display cells (truncate first if needed)."""
+    if _text_display_width(s) > width:
+        s = _fit_display_width(s, width)
+    pad = width - _text_display_width(s)
+    return s + (" " * max(0, pad))
+
+
+def print_sessions_table(
+    sessions: list,
+    *,
+    has_titles: bool,
+    indent: str = "",
+) -> None:
+    """Print session rows with terminal-accurate column alignment (CJK-safe).
+
+    Plain ``str.ljust`` / f-string padding counts Unicode code points, not
+    terminal cell width, which breaks mixed Chinese/Latin rows.
+    """
+
+    def _row_titled(title: str, preview: str, last_active: str, sid: str) -> str:
+        return (
+            f"{_pad_display_right(title, 32)} {_pad_display_right(preview, 40)} "
+            f"{_pad_display_right(last_active, 13)} {sid}"
+        )
+
+    def _row_plain(preview: str, last_active: str, src: str, sid: str) -> str:
+        return (
+            f"{_pad_display_right(preview, 50)} {_pad_display_right(last_active, 13)} "
+            f"{_pad_display_right(src, 6)} {sid}"
+        )
+
+    if has_titles:
+        header = _row_titled("Title", "Preview", "Last Active", "ID")
+        rule_w = min(_text_display_width(header) + 4, 120)
+        print(f"{indent}{header}")
+        print(f"{indent}{'─' * rule_w}")
+        for s in sessions:
+            title = s.get("title") or "—"
+            preview = s.get("preview") or ""
+            last_active = _relative_time(s.get("last_active"))
+            sid = s.get("id") or ""
+            print(f"{indent}{_row_titled(title, preview, last_active, sid)}")
+    else:
+        header = _row_plain("Preview", "Last Active", "Src", "ID")
+        rule_w = min(_text_display_width(header) + 4, 120)
+        print(f"{indent}{header}")
+        print(f"{indent}{'─' * rule_w}")
+        for s in sessions:
+            preview = s.get("preview") or ""
+            last_active = _relative_time(s.get("last_active"))
+            src = s.get("source") or ""
+            sid = s.get("id") or ""
+            print(f"{indent}{_row_plain(preview, last_active, src, sid)}")
+
+
 def _relative_time(ts) -> str:
     """Format a timestamp as relative time (e.g., '2h ago', 'yesterday')."""
     if not ts:
@@ -5576,22 +5662,7 @@ Examples:
                 print("No sessions found.")
                 return
             has_titles = any(s.get("title") for s in sessions)
-            if has_titles:
-                print(f"{'Title':<32} {'Preview':<40} {'Last Active':<13} {'ID'}")
-                print("─" * 110)
-            else:
-                print(f"{'Preview':<50} {'Last Active':<13} {'Src':<6} {'ID'}")
-                print("─" * 95)
-            for s in sessions:
-                last_active = _relative_time(s.get("last_active"))
-                preview = s.get("preview", "")[:38] if has_titles else s.get("preview", "")[:48]
-                if has_titles:
-                    title = (s.get("title") or "—")[:30]
-                    sid = s["id"]
-                    print(f"{title:<32} {preview:<40} {last_active:<13} {sid}")
-                else:
-                    sid = s["id"]
-                    print(f"{preview:<50} {last_active:<13} {s['source']:<6} {sid}")
+            print_sessions_table(sessions, has_titles=has_titles)
 
         elif action == "export":
             if args.session_id:

tests/hermes_cli/test_session_display_width.py

@@ -0,0 +1,133 @@
+"""Tests for CJK-aware session list column padding (hermes_cli.main display helpers)."""
+
+from unittest.mock import patch
+
+from hermes_cli.main import (
+    _fit_display_width,
+    _pad_display_right,
+    _text_display_width,
+    print_sessions_table,
+)
+
+
+class TestTextDisplayWidth:
+    def test_empty(self) -> None:
+        assert _text_display_width("") == 0
+
+    def test_ascii(self) -> None:
+        assert _text_display_width("abc") == 3
+
+    def test_wide_cjk(self) -> None:
+        # Typical Han characters are wide (W) — two terminal cells each.
+        assert _text_display_width("中文") == 4
+
+    def test_mixed(self) -> None:
+        assert _text_display_width("a中") == 1 + 2
+
+
+class TestFitDisplayWidth:
+    def test_no_truncation_when_fits(self) -> None:
+        assert _fit_display_width("hello", 10) == "hello"
+
+    def test_truncates_with_ellipsis(self) -> None:
+        out = _fit_display_width("abcdefghij", 5)
+        assert out.endswith("…")
+        assert _text_display_width(out) <= 5
+
+    def test_cjk_truncation_respects_cells(self) -> None:
+        s = "一二三四五六"
+        out = _fit_display_width(s, 5)
+        assert out.endswith("…")
+        assert _text_display_width(out) <= 5
+
+    def test_max_cells_zero_returns_empty(self) -> None:
+        assert _fit_display_width("hello", 0) == ""
+
+
+class TestPadDisplayRight:
+    def test_pads_ascii_to_width(self) -> None:
+        assert _pad_display_right("hi", 8) == "hi      "
+        assert _text_display_width(_pad_display_right("hi", 8)) == 8
+
+    def test_pads_mixed_to_display_width(self) -> None:
+        # "a" + two wide chars = 1 + 4 = 5 cells; pad to 8 → 3 spaces
+        got = _pad_display_right("a中文", 8)
+        assert _text_display_width(got) == 8
+        assert got.startswith("a中文")
+
+    def test_truncates_before_pad_when_too_long(self) -> None:
+        long = "x" * 80
+        got = _pad_display_right(long, 8)
+        assert _text_display_width(got) == 8
+        assert got.endswith("…")
+
+
+class TestPrintSessionsTable:
+    """Smoke + fixed-clock integration so Last Active is deterministic."""
+
+    def test_with_titles_prints_header_and_row(self, capsys) -> None:
+        fixed_now = 1_700_000_000.0
+        with patch("hermes_cli.main._time.time", return_value=fixed_now):
+            print_sessions_table(
+                [
+                    {
+                        "title": "Rust 项目",
+                        "preview": "分析当前",
+                        "last_active": fixed_now - 400,
+                        "id": "20260415_testsession",
+                    }
+                ],
+                has_titles=True,
+            )
+        out = capsys.readouterr().out
+        assert "Title" in out and "Preview" in out and "Last Active" in out
+        assert "Rust 项目" in out
+        assert "20260415_testsession" in out
+        assert "6m ago" in out
+        lines = [ln for ln in out.splitlines() if ln.strip()]
+        assert len(lines) >= 3
+
+    def test_without_titles_includes_source(self, capsys) -> None:
+        fixed_now = 1_700_000_000.0
+        with patch("hermes_cli.main._time.time", return_value=fixed_now):
+            print_sessions_table(
+                [
+                    {
+                        "preview": "hello",
+                        "last_active": fixed_now - 90,
+                        "source": "cli",
+                        "id": "id_only",
+                    }
+                ],
+                has_titles=False,
+            )
+        out = capsys.readouterr().out
+        assert "Preview" in out and "Src" in out
+        assert "cli" in out and "id_only" in out
+
+    def test_indent_prefix(self, capsys) -> None:
+        fixed_now = 1_700_000_000.0
+        with patch("hermes_cli.main._time.time", return_value=fixed_now):
+            print_sessions_table(
+                [{"title": "t", "preview": "p", "last_active": fixed_now, "id": "i"}],
+                has_titles=True,
+                indent="  ",
+            )
+        out = capsys.readouterr().out
+        for line in out.splitlines():
+            if line.strip():
+                assert line.startswith("  ")
+
+    def test_row_columns_have_expected_display_widths(self) -> None:
+        """Guardrail: titled row layout matches fixed column budgets + spaces."""
+        title = _pad_display_right("ColdStore Rust 项目", 32)
+        preview = _pad_display_right("分析当前项目", 40)
+        last = _pad_display_right("6m ago", 13)
+        sid = "20260415_081027_6b979d"
+        line = f"{title} {preview} {last} {sid}"
+        assert _text_display_width(title) == 32
+        assert _text_display_width(preview) == 40
+        assert _text_display_width(last) == 13
+        # Single space between padded columns, then unbounded id.
+        assert line == f"{title} {preview} {last} {sid}"
+