docs: update calc-02 portrait visual reference

Move the portrait layout documentation to samples/calc-02/visual-portrait.md and refresh the project memory note to point to the new reference.

.memory/project.md

@@ -5,5 +5,5 @@
 - Public API: `push`, `pop`, `clear`, `swap`, `remove`, `edit`, `isValidIndex`, `input`, `command`, `getOperationsByCategory`, `getConstants`, `listConstants`, `setConstant`, `removeConstant`, `hasConstant`
 - Config: `maxSize`, `base`, `angleMode`, `enabledCommands`
 - Commands: arithmetic, stack, trigonometry, constants `pi` and `e`; arithmetic now includes `root` for y-th roots; constants can now be added or removed dynamically through the core API and the calc-02 constant menu reads from the engine
-- Demo actions: keyboard focus is kept on the hidden input on desktop so typing keeps working; the keypad layout places Enter in the bottom-left, ± in the former Enter position, and Esc before Clear for safety; paste parses clipboard text as a number before pushing it to the stack; Ctrl+V is supported via the hidden input paste event; backspace is ignored when the stack is empty; operation errors are shown as an overlay bar on top of the calculator with a shorter timeout and darker red; the display button row uses a 4-column grid with a spacer cell to preserve alignment
+- Demo actions: keyboard focus is kept on the hidden input on desktop so typing keeps working; the keypad layout places Enter in the bottom-left, ± in the former Enter position, and Esc before Clear for safety; paste parses clipboard text as a number before pushing it to the stack; Ctrl+V is supported via the hidden input paste event; backspace is ignored when the stack is empty; operation errors are shown as an overlay bar on top of the calculator with a shorter timeout and darker red; the display button row uses a 4-column grid with a spacer cell to preserve alignment; the portrait layout reference now lives in `samples/calc-02/visual-portrait.md`
 - Exports: browser `window.RpnCalculator`, CommonJS `module.exports`

samples/calc-02/visual-landscape.txt

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

samples/calc-02/visual-portrait.md

@@ -0,0 +1,52 @@
+# Calc 02 Visual Portrait
+
+## Display
+
+```
+┌──────────── Display ────────────┐
+| T:                              |
+| Z:                              |
+| Y:                              |
+| X:                              |
+└─────────────────────────────────┘
+```
+
+## Display Buttons
+
+```
+┌──────── Display Buttons ────────┐
+| Mode  | Paste  | Up    | Const  |
+|       | Left   | Down  | Right  |
+└─────────────────────────────────┘
+```
+
+## Keypad
+
+```
+┌───────────── 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    |       |             |
+└───────────────────────────────────┘
+```
+
+## Trigo
+
+```
+┌───────────── Trigo ───────────────┐
+| sin  | cos   | tan   |            |
+| asin | acos  | atan  |            |
+└───────────────────────────────────┘
+```

samples/calc-02/visual-portrait.txt

@@ -1,26 +0,0 @@
-┌──────────── Display ────────────┐
-| T:                              |
-| Z:                              |
-| Y:                              |
-| X:                              |
-└─────────────────────────────────┘
-┌──────── Display Buttons ────────┐
-| Mode  | Paste  | Up    | Const  |
-|       | Right  | Down  | Right  |
-└─────────────────────────────────┘
-┌──────────── Keypad ─────────────┐
-| +/- | Clear | Esc   | backspace |
-| 7   | 8     | 9     | /         |
-| 4   | 5     | 6     | *         |
-| 1   | 2     | 3     | -         |
-| 0   | .     | Enter | +         |
-└─────────────────────────────────┘
-┌─────────── Functions ───────────┐
-| x^2 | y^x   | 1/x   | %         |
-| √x  | y√x   | 10^x  |           |
-| log | ln    |       |           |
-└─────────────────────────────────┘
-┌───────────── Trigo ─────────────┐
-| sin  | cos   | tan  |           |
-| asin | acos  | atan |           |
-└─────────────────────────────────┘