feat: implement tweaks plan - modals, smart shell, spinner, /models, debug log, skills

Phase 1: Permission modal dialog, session resume modal, HistoryInput with
up/down arrow cycling, remove "You:" echo from chat log, LLM client cleanup
on unmount.

Phase 2: Smart shell auto-approve using allowed/denied command lists from
ToolsConfig, animated thinking spinner with live token count in status bar.

Phase 3: /models slash command (list + switch), CLI directory positional
argument, JSONL debug logger with rotation.

Phase 4: Skills system with SkillsManager, load_skill LLM tool, /skills
listing, skill invocation via slash commands, system prompt integration.

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

app/ui/widgets.py

@@ -2,12 +2,130 @@
 
 from __future__ import annotations
 
+from textual.app import ComposeResult
+from textual.containers import Horizontal, Vertical
+from textual.events import Key
+from textual.screen import ModalScreen
+from textual.timer import Timer
+from textual.widgets import Button, Input, Static
+
 from rich.text import Text
-from textual.widgets import Static
+
+
+# ---------------------------------------------------------------------------
+# Modal Dialogs
+# ---------------------------------------------------------------------------
+
+
+class PermissionModal(ModalScreen[bool]):
+    """Modal dialog for tool permission approval."""
+
+    BINDINGS = [("y", "allow", "Allow"), ("n", "deny", "Deny")]
+
+    def __init__(self, tool_name: str, description: str) -> None:
+        super().__init__()
+        self._tool_name = tool_name
+        self._description = description
+
+    def compose(self) -> ComposeResult:
+        with Vertical(id="permission-dialog"):
+            yield Static(f"Tool: {self._tool_name}", classes="modal-title")
+            yield Static(self._description, classes="modal-body")
+            with Horizontal(classes="modal-buttons"):
+                yield Button("Allow (y)", id="allow", variant="success")
+                yield Button("Deny (n)", id="deny", variant="error")
+
+    def on_button_pressed(self, event: Button.Pressed) -> None:
+        self.dismiss(event.button.id == "allow")
+
+    def action_allow(self) -> None:
+        self.dismiss(True)
+
+    def action_deny(self) -> None:
+        self.dismiss(False)
+
+
+class SessionResumeModal(ModalScreen[bool]):
+    """Modal dialog for session resume prompt."""
+
+    BINDINGS = [("y", "resume", "Resume"), ("n", "fresh", "Start Fresh")]
+
+    def __init__(self, msg_count: int) -> None:
+        super().__init__()
+        self._msg_count = msg_count
+
+    def compose(self) -> ComposeResult:
+        with Vertical(id="permission-dialog"):
+            yield Static("Resume Session?", classes="modal-title")
+            yield Static(
+                f"Found previous session with {self._msg_count} messages.",
+                classes="modal-body",
+            )
+            with Horizontal(classes="modal-buttons"):
+                yield Button("Resume (y)", id="resume", variant="success")
+                yield Button("Start Fresh (n)", id="fresh", variant="warning")
+
+    def on_button_pressed(self, event: Button.Pressed) -> None:
+        self.dismiss(event.button.id == "resume")
+
+    def action_resume(self) -> None:
+        self.dismiss(True)
+
+    def action_fresh(self) -> None:
+        self.dismiss(False)
+
+
+# ---------------------------------------------------------------------------
+# Input with History
+# ---------------------------------------------------------------------------
+
+
+class HistoryInput(Input):
+    """Input with up/down arrow history cycling."""
+
+    def __init__(self, **kwargs: object) -> None:
+        super().__init__(**kwargs)
+        self._history: list[str] = []
+        self._history_index: int = -1
+        self._draft: str = ""
+
+    def record(self, value: str) -> None:
+        """Record a submitted value in history."""
+        if value.strip() and (not self._history or self._history[-1] != value):
+            self._history.append(value)
+        self._history_index = -1
+        self._draft = ""
+
+    def on_key(self, event: Key) -> None:
+        if event.key == "up" and self._history:
+            event.prevent_default()
+            if self._history_index == -1:
+                self._draft = self.value
+                self._history_index = len(self._history) - 1
+            elif self._history_index > 0:
+                self._history_index -= 1
+            self.value = self._history[self._history_index]
+            self.cursor_position = len(self.value)
+        elif event.key == "down" and self._history_index != -1:
+            event.prevent_default()
+            self._history_index += 1
+            if self._history_index >= len(self._history):
+                self._history_index = -1
+                self.value = self._draft
+            else:
+                self.value = self._history[self._history_index]
+            self.cursor_position = len(self.value)
+
+
+# ---------------------------------------------------------------------------
+# Status Bar
+# ---------------------------------------------------------------------------
 
 
 class StatusBar(Static):
-    """Single-line status bar showing token usage and iteration count."""
+    """Single-line status bar showing token usage, iteration count, and streaming spinner."""
+
+    _SPINNER = "\u280b\u2819\u2839\u2838\u283c\u2834\u2826\u2827\u2807\u280f"
 
     DEFAULT_CSS = """
     StatusBar {
@@ -25,6 +143,10 @@ class StatusBar(Static):
         self._budget: int = 0
         self._iteration: int = 0
         self._max_iterations: int = 0
+        self._streaming: bool = False
+        self._spinner_frame: int = 0
+        self._spinner_timer: Timer | None = None
+        self._stream_tokens: int = 0
 
     def update_tokens(self, tokens: int, budget: int) -> None:
         """Update the token usage display."""
@@ -38,14 +160,48 @@ class StatusBar(Static):
         self._max_iterations = max_iterations
         self._refresh_display()
 
+    def start_streaming(self) -> None:
+        """Start the animated thinking spinner."""
+        self._streaming = True
+        self._spinner_frame = 0
+        self._stream_tokens = 0
+        self._spinner_timer = self.set_interval(0.08, self._tick_spinner)
+        self._refresh_display()
+
+    def stop_streaming(self) -> None:
+        """Stop the animated thinking spinner."""
+        self._streaming = False
+        if self._spinner_timer:
+            self._spinner_timer.stop()
+            self._spinner_timer = None
+        self._refresh_display()
+
+    def update_stream_tokens(self, tokens: int) -> None:
+        """Update estimated token count during streaming."""
+        self._stream_tokens = tokens
+
+    def _tick_spinner(self) -> None:
+        self._spinner_frame = (self._spinner_frame + 1) % len(self._SPINNER)
+        self._refresh_display()
+
     def _refresh_display(self) -> None:
         """Rebuild the status bar text."""
         parts: list[str] = []
+        if self._streaming:
+            spinner = self._SPINNER[self._spinner_frame]
+            parts.append(f"{spinner} Thinking")
+            if self._stream_tokens > 0:
+                parts.append(f"~{self._stream_tokens:,} tokens")
         if self._budget > 0:
             parts.append(f"Tokens: ~{self._tokens:,} / {self._budget:,}")
         if self._max_iterations > 0:
             parts.append(f"Iteration {self._iteration}/{self._max_iterations}")
-        self.update(Text(" │ ".join(parts), style="dim"))
+        self.update(Text(" \u2502 ".join(parts), style="dim"))
+
+
+# ---------------------------------------------------------------------------
+# Streaming Display
+# ---------------------------------------------------------------------------
 
 
 class StreamingStatic(Static):