fix(calc-02): reorder display buttons in portrait layout

.memory/project.md

@@ -1,6 +1,6 @@
 # State
 - Core engine: `src/rpn-calculator.js`
-- Reference demo: `samples/calc-02/` (portrait-first HP48GX layout, compact mode/constants popups)
+- Reference demo: `samples/calc-02/` (portrait-first HP48GX layout, compact mode/constants popups; Const button comes before Mode in the display row)
 - Important UI behavior: mode button shows the current angle mode; keyboard focus stays on the hidden input on desktop; clipboard paste is supported
 - Public API: `push`, `pop`, `clear`, `swap`, `remove`, `edit`, `isValidIndex`, `input`, `command`, `getOperationsByCategory`, `getConstants`, `listConstants`, `setConstant`, `removeConstant`, `hasConstant`
 - Config: `maxSize`, `base`, `angleMode`, `enabledCommands`

samples/calc-02/index.html

@@ -25,11 +25,11 @@
 
 			<div class="display-buttons-panel">
 				<div class="display-buttons-grid">
-					<button id="modeButton" class="display-button">Mode</button>
 					<button id="constButton" class="display-button">π</button>
-					<button id="upButton" class="display-button"><span class="display-button-symbol arrow-symbol">↑</span></button>
-					<div class="display-button-spacer"></div>
 					<button id="pasteButton" class="display-button"><span class="display-button-symbol paste-symbol">⎘</span></button>
+					<button id="upButton" class="display-button"><span class="display-button-symbol arrow-symbol">↑</span></button>
+					<button id="modeButton" class="display-button">Mode</button>
+					<div class="display-button-spacer"></div>
 					<button id="leftButton" class="display-button display-button-offset"><span class="display-button-symbol arrow-symbol">←</span></button>
 					<button id="downButton" class="display-button"><span class="display-button-symbol arrow-symbol">↓</span></button>
 					<button id="rightButton" class="display-button"><span class="display-button-symbol arrow-symbol">→</span></button>

samples/calc-02/visual-portrait.md

@@ -15,7 +15,7 @@
 
 ```
 ┌──────── Display Buttons ────────┐
-| Mode  | Paste  | Up    | Const  |
+| Const | Paste  | Up    | Mode   |
 |       | Left   | Down  | Right  |
 └─────────────────────────────────┘
 ```
@@ -23,30 +23,30 @@
 ## Keypad
 
 ```
-┌───────────── Keypad ──────────────┐
-| +/-   | Clear | Esc   | backspace |
-| 7     | 8     | 9     | /         |
-| 4     | 5     | 6     | *         |
-| 1     | 2     | 3     | -         |
-| 0     | .     | Enter | +         |
-└───────────────────────────────────┘
+┌──────────── Keypad ─────────────┐
+| +/- | Clear | Esc   | backspace |
+| 7   | 8     | 9     | /         |
+| 4   | 5     | 6     | *         |
+| 1   | 2     | 3     | -         |
+| 0   | .     | Enter | +         |
+└─────────────────────────────────┘
 ```
 
 ## Functions
 
 ```
-┌──────────── Functions ────────────┐
-| x^2 | y^x   | 1/x   | %           |
-| √x  | y√x   | 10^x  |             |
-| log | ln    |       |             |
-└───────────────────────────────────┘
+┌──────────── Functions ──────────┐
+| x^2  | y^x   | 1/x   | %        |
+| √x   | y√x   | 10^x  |          |
+| log  | ln    |       |          |
+└─────────────────────────────────┘
 ```
 
 ## Trigo
 
 ```
-┌───────────── Trigo ───────────────┐
-| sin  | cos   | tan   |            |
-| asin | acos  | atan  |            |
-└───────────────────────────────────┘
+┌──────────── Trigo ──────────────┐
+| sin  | cos   | tan   |          |
+| asin | acos  | atan  |          |
+└─────────────────────────────────┘
 ```