Add search button to top bar, move cursor info to bottom bar

StatusBar (top bar):
- Added Search icon (always visible, toggles search bar)
- Removed cursor position from top bar (moved to bottom bar)
- Fixed icon slots: Cut, Copy, Search, Paste (left to right)
- File size between Paste and Conflict icons

BottomBar (new element):
- Always visible at bottom of editor page (24 DP fixed height)
- Left: cursor position (Ln X, Col Y)
- Right: word wrap status (On/Off)
- Cursor position updated on every cursor movement
- Word wrap status persisted to .pad/state.json

Search button:
- Tap toggles search bar visible/invisible
- When active: shows SearchBar element, focuses text field, shows keyboard
- When inactive: hides SearchBar, clears query, hides keyboard
- Primary search activation method on Android (Ctrl+F still works as secondary)

Layout:
- Top: StatusBar (filename + action icons)
- Middle: SearchBar (when active) + TextField (editor)
- Bottom: BottomBar (cursor position + word wrap status)

Co-authored-by: Qwen-Coder <qwen-coder@alibabacloud.com>

doc/element_model.md

@@ -215,10 +215,10 @@ type StatusBar struct {
     /* region, visible, id — unexported */
     Filename     string  // e.g., "notes.txt" (truncated with ellipsis if too long)
     FilenameExp  bool    // true = show full filename (multi-line), false = truncated
-    Left         string  // e.g., "Ln 10, Col 5"
     Right        string  // e.g., "1024 / 50000 bytes"
     CutCopy      bool    // true = show cut icon in left slot
     Copy         bool    // true = show copy icon in left slot (next to cut)
+    Search       bool    // true = show search icon (toggle search bar)
     Paste        bool    // true = show paste icon in right slot
     ConflictIcon bool    // true = show conflict warning icon (rightmost)
 }
@@ -227,19 +227,44 @@ type StatusBar struct {
 The status bar appears at the top of the editor page. It has a **two-line layout**:
 
 - **Line 1**: Filename (truncated with ellipsis if too long). Tapping the ellipsis toggles between truncated and full multi-line view.
-- **Line 2**: Action icons (Cut, Copy, Paste) + line/col info + file size + conflict icon.
+- **Line 2**: Action icons (Cut, Copy, Search, Paste) + file size + conflict icon.
 
 **Fixed icon slots** (24×24 DP each, fixed positions):
 - **Cut icon**: leftmost action icon
 - **Copy icon**: second from left (36 DP from Cut icon)
-- **Paste icon**: second from right
+- **Search icon**: third from left (36 DP from Copy icon)
+- **Paste icon**: fourth from left (36 DP from Search icon)
 - **Conflict icon**: rightmost
 
 Icons appear/disappear without reflowing other elements. The StatusBar's `Region.H` is computed dynamically based on whether the filename is truncated (2 lines) or expanded (3+ lines).
 
 When a sync conflict is detected for the active file, `ConflictIcon` is set to true. Tapping the icon navigates to the merge resolution page. The icon persists across process death — if a conflict file exists for the active file on restore, the icon appears.
 
-### 3.10 Toast / Notification
+### 3.10 Bottom Bar
+
+```go
+type BottomBar struct {
+    /* region, visible, id — unexported */
+    CursorPos    string  // e.g., "Ln 10, Col 5"
+    WordWrap     bool    // true = word wrap is enabled (shown for reference)
+}
+```
+
+The bottom bar appears at the bottom of the editor page. It displays cursor position and editor state information. It is always visible (no icons, just text).
+
+**Layout**:
+```
+┌──────────────────────────────────────────────────────────────┐
+│  Ln 10, Col 5    Word Wrap: On                               │
+└──────────────────────────────────────────────────────────────┘
+```
+
+- **Left**: Cursor position (line number, column number)
+- **Right**: Word wrap status (On/Off)
+
+The BottomBar's `Region.H` is fixed (24 DP). It sits below the editor content.
+
+### 3.11 Toast / Notification
 
 ```go
 type Toast struct {
@@ -318,11 +343,11 @@ Elements are rendered in slice order. Later elements draw on top of earlier ones
 
 ```
 1. Background (full screen)
-2. Header / Label
+2. Status bar (top)
 3. Search bar or main content
 4. List or text area
-5. Overlay elements (cursor, selection highlight, toast)
+5. Overlay elements (cursor, selection highlight)
-6. Status bar (bottom)
+6. Bottom bar
 ```
 
 ## 7. Theme
@@ -356,12 +381,13 @@ Elements that don't specify explicit colors/sizes use theme defaults. The theme
 []Element{
     StatusBar{
         Filename: "notes.txt", FilenameExp: false,
-        Left: "Ln 47, Col 12", Right: "1024 / 50000",
+        Right: "1024 / 50000",
-        CutCopy: true, Copy: false, Paste: true, ConflictIcon: false,
+        CutCopy: true, Copy: false, Search: false, Paste: true, ConflictIcon: false,
     },
     SearchBar{Query: "foo", Match: 1, Total: 3},    // search (when active)
     TextField{Multiline: true, VisibleLines: [...], ScrollOffset: 420, WordWrap: true},
     Cursor{Line: 5, Column: 12, Selection: &Selection{...}},
+    BottomBar{CursorPos: "Ln 47, Col 12", WordWrap: true},
 }
 ```
 
@@ -369,10 +395,13 @@ The search bar is only present when the user has activated search. When visible,
 
 The StatusBar contains:
 - **Filename** on line 1 (truncated with ellipsis if too long)
-- **Action icons** (Cut, Copy, Paste) on line 2, fixed positions
+- **Action icons** (Cut, Copy, Search, Paste) on line 2, fixed positions
-- **Line/col info** between Cut/Copy and Paste icons
 - **File size** between Paste and Conflict icons
 
+The BottomBar contains:
+- **Cursor position** on the left (e.g., "Ln 47, Col 12")
+- **Word wrap status** on the right (e.g., "Word Wrap: On")
+
 ### 8.3 Merge Page
 
 ```

doc/touch.md

@@ -303,17 +303,24 @@ The StatusBar (top bar) has **fixed icon slots** for cut, copy, and paste. Icons
 ```
 ┌──────────────────────────────────────────────────────────────┐
 │  filename.txt                                                │  ← Line 1: filename (truncated with ellipsis)
-│  [Cut] [Copy]  Ln 10, Col 5  [Paste]  1024 / 50000  [Conf] │  ← Line 2: action icons + info
+│  [Cut] [Copy] [Search] [Paste] 1024 / 50000  [Conf]         │  ← Line 2: action icons + file size
+└──────────────────────────────────────────────────────────────┘
+         StatusBar (top bar)
+┌──────────────────────────────────────────────────────────────┐
+│  TextField (editor content)                                  │
+└──────────────────────────────────────────────────────────────┘
+┌──────────────────────────────────────────────────────────────┐
+│  Ln 10, Col 5    Word Wrap: On                               │  ← BottomBar
 └──────────────────────────────────────────────────────────────┘
 ```
 
 **Fixed slot positions** (in Dp, from the edges):
 - **Cut icon**: leftmost action icon (24×24 DP, fixed position)
 - **Copy icon**: second from left (24×24 DP, fixed position, 36 DP from Cut icon)
-- **Paste icon**: second from right (24×24 DP, fixed position)
+- **Search icon**: third from left (24×24 DP, fixed position, 36 DP from Copy icon)
+- **Paste icon**: fourth from left (24×24 DP, fixed position, 36 DP from Search icon)
 - **Conflict icon**: rightmost (24×24 DP, fixed position)
 - **Filename**: top line, truncated with ellipsis if too long
-- **Line/col info**: between Cut/Copy and Paste icons
 - **File size**: between Paste and Conflict icons
 
 **Visibility rules**:
@@ -322,6 +329,7 @@ The StatusBar (top bar) has **fixed icon slots** for cut, copy, and paste. Icons
 |---|---|
 | **Cut** | `selection_start != selection_end` |
 | **Copy** | `selection_start != selection_end` |
+| **Search** | Always visible (toggle search bar) |
 | **Paste** | `clipboard != ""` |
 | **Conflict** | sync conflict detected for active file |
 
@@ -344,6 +352,25 @@ Icons are rendered as `Button` elements with fixed sizes. The StatusBar's `Regio
 4. Selection is **not** cleared (text remains in buffer).
 5. Logic produces a new frame (Cut/Copy icons still visible, Paste icon appears).
 
+### 5.6.4a Search Button
+
+The Search button toggles the search bar visible/invisible.
+
+1. User taps the Search icon.
+2. Logic toggles `search_active` state field.
+3. If `search_active` is true:
+   - Show `SearchBar` element below the StatusBar.
+   - Set focus to the search bar's text field.
+   - Show the soft keyboard (`key.SoftKeyboardOp(true)`).
+4. If `search_active` is false:
+   - Hide `SearchBar` element.
+   - Clear search query.
+   - Remove focus from search bar.
+   - Hide soft keyboard (`key.SoftKeyboardOp(false)`).
+5. Logic produces a new frame.
+
+The Search button is always visible in the StatusBar (unlike Cut/Copy/Paste which are conditional). It serves as the primary way to activate search on Android (where Ctrl+F may not be available).
+
 ### 5.6.5 Paste Operation
 
 1. User taps the Paste icon.
@@ -406,16 +433,48 @@ This field is **not** persisted to disk — it is reset on app restart (same as
 In the truncated view, the StatusBar has 2 lines:
 ```
 Line 1: filename.txt...
-Line 2: [Cut] [Copy]  Ln 10, Col 5  [Paste]  1024 / 50000  [Conf]
+Line 2: [Cut] [Copy] [Search] [Paste] 1024 / 50000  [Conf]
 ```
 
 In the full view, the StatusBar has 3+ lines (depending on filename length):
 ```
 Line 1: very_long_filename_that_does_not_fit_on_a_single_line.txt
-Line 2: [Cut] [Copy]  Ln 10, Col 5  [Paste]  1024 / 50000  [Conf]
+Line 2: [Cut] [Copy] [Search] [Paste] 1024 / 50000  [Conf]
 ```
 
-The `Region.H` of the StatusBar is computed dynamically based on the number of lines.
+The `Region.H` of the StatusBar is computed dynamically based on the number of lines. The BottomBar is always at the bottom of the screen (24 DP fixed height).
+
+## 5.8 Bottom Bar
+
+The Bottom Bar appears at the bottom of the editor page. It displays cursor position and editor state information. It is always visible (no icons, just text).
+
+### 5.8.1 Layout
+
+```
+┌──────────────────────────────────────────────────────────────┐
+│  Ln 10, Col 5    Word Wrap: On                               │
+└──────────────────────────────────────────────────────────────┘
+```
+
+- **Left**: Cursor position (e.g., "Ln 10, Col 5")
+- **Right**: Word wrap status (e.g., "Word Wrap: On")
+
+The BottomBar's `Region.H` is fixed at 24 DP. It sits below the editor content.
+
+### 5.8.2 Cursor Position
+
+The cursor position is computed from the current byte offset:
+1. Logic converts byte offset to (line, column) using the **Line Index**.
+2. The `CursorPos` field is set to `"Ln {line}, Col {column}"`.
+3. The field is updated on every cursor movement (tap, arrow keys, backspace, etc.).
+
+### 5.8.3 Word Wrap Status
+
+The word wrap status is a simple boolean field (`word_wrap_enabled`):
+- `true` → "Word Wrap: On"
+- `false` → "Word Wrap: Off"
+
+This field is persisted to `.pad/state.json` and restored on app start. Toggling word wrap is done via a settings screen (not yet implemented).
 
 ## 6. Scroll Momentum