feat: mirror pane (p), cursor memory, clean up help dialog

- Add Mirror pane keybinding p (for 'Pane'), SSH restored on s
- Add session-scoped cursor memory per directory
- Fix cursor memory bug: DisplayName() adds trailing / for directories
- Fix remote mirror: use active.Path instead of mount.RemotePath
- Remove F-key/Mouse/b/c entries from F1 help dialog
- Remove Mirror from ShortHelp footer (F-keys only)
- Add missing letter-key bindings to help: p, s, a, n, x

plans/mirror-and-cursor-memory.md

@@ -0,0 +1,88 @@
+# Feature Plan: Mirror Pane & Per-Directory Cursor Memory
+
+## Feature 1: Mirror active pane directory to opposite pane
+
+### Keybinding research
+- **Midnight Commander (MC)**: `Alt-i` — makes the other panel equal to current directory
+- **Total Commander**: `Ctrl-PgDn` opens directory under cursor in opposite panel
+- **Far Manager**: `Ctrl-Left/Right` — opens in opposite panel
+
+**Recommendation**: Bind to `p` (for "Pane"). `Ctrl-i` sends the same byte as `Tab` (ASCII 0x09) so it conflicts with Switch. `p` is free, accessible, and "Pane" reflects the meaning.
+
+### How it works
+1. Read active pane's current path (including remote mount state)
+2. Apply that path to the passive (opposite) pane
+3. If active is in a remote mount, also clone the remote mount stack to the passive pane
+4. Reload both panes to reflect the change
+
+### Code changes
+
+#### [`internal/ui/keymap.go`](internal/ui/keymap.go)
+- Add `Mirror` key binding field to `KeyMap` struct
+- Bind to `"p"` with help text `"p"` / `"mirror pane"`
+
+#### [`internal/ui/model.go`](internal/ui/model.go)
+- Add handler `handleMirrorPane()`:
+  1. Get active pane path and remote mount state
+  2. Switch passive pane to match (copy remote stack if applicable)
+  3. Reload passive pane (using `reloadPane` or `reloadRemotePane`)
+  4. Set status: `"Mirrored: <path>"`
+- Add key match case before the `default` switch
+
+---
+
+## Feature 2: Per-directory cursor position memory (session scope)
+
+### Current state
+- `enterSelected()` saves `pane.Path` to history for back-nav, then reloads target dir with `selected.Name` as preserve key — but `selected.Name` is the name of the directory being entered, not a cursor anchor
+- `goParent()` pops history and reloads parent using the child directory name as preserve — cursor lands on the directory we came from
+- **Missing**: When navigating back into a previously-visited directory, there's no saved cursor position for it
+
+### Design
+Add a `cursorMemory` field to `BrowserPane` — a `map[string]string` mapping **directory path → last selected entry display name**.
+
+This integrates cleanly with the existing `SetEntries(entries, preserveKey)` / `FindSelected()` infrastructure.
+
+### Flow
+
+```
+enterSelected() / enterRemoteDir():
+  1. Save to cursorMemory: pane.Path → selected entry's Name
+  2. Push history (existing)
+  3. Set path, reload (existing)
+  4. The reload already uses preserve=selected.Name for the new dir,
+     but cursorMemory will help when coming back later
+
+reloadPane() / reloadRemotePane():
+  1. Try preserve key first (existing behavior)
+  2. If preserve is empty, check cursorMemory[pane.Path]
+     and use that as preserveKey instead
+```
+
+### Code changes
+
+#### [`internal/ui/pane.go`](internal/ui/pane.go)
+- Add field to `BrowserPane`: `CursorMemory map[string]string`
+- Method `SaveCursor(path string, name string)` — stores cursor position
+- Method `LoadCursor(path string) string` — retrieves saved cursor
+
+#### [`internal/ui/model.go`](internal/ui/model.go)
+- In `enterSelected()` (line ~1886): after `pane.PushHistory(pane.Path)`, add `pane.SaveCursor(pane.Path, selected.Name)`
+- In `enterRemoteDir()` (line ~5726): same save logic
+- In `goParent()`: save cursor before navigating away (already partially done via history)
+- In `reloadPane()` (line ~1672): after existing preserve logic, if no preserve key and directory has cursor memory, use it
+- In `reloadRemotePane()` (line ~5535): same fallback
+
+---
+
+## Files modified
+| File | Changes |
+|------|---------|
+| `internal/ui/keymap.go` | Add `Mirror` field, binding `p` |
+| `internal/ui/pane.go` | Add `CursorMemory` field + methods |
+| `internal/ui/model.go` | Add `handleMirrorPane()`, save/restore cursor in navigation methods |
+
+## Not changed
+- `internal/fs/` — storage layer unaffected
+- `internal/config/` — no config changes needed
+- `internal/theme/` — no theme changes needed