fix: assorted bug fixes for lists, sounds, interrupts, and permissions (#173)

## Summary

- **Markdown lists**: Explicitly set `list-style-type: disc` / `decimal` in the Markdown renderer — Tauri's WebView strips browser defaults, leaving bullets and numbers invisible.
- **Notification sounds**: Moved all per-task sounds (success, error, permission, task-start) from a global `characterState` subscription into the per-conversation `claude:state` event handler, so background tabs receive their sounds correctly and tab-switching never replays a sound that already fired. Closes #172
- **Draft text**: Persists `inputValue` per conversation tab so a half-typed prompt survives switching to another tab and back.
- **Interrupt messages**: Replaced vague "Process interrupted" / "Disconnected" strings with source-specific descriptions (keyboard shortcut, stop button, unexpected crash) so it's clear what actually happened.
- **Silent prompt loss**: When Claude Code exits whilst a prompt is in-flight, emits a visible error line telling the user their last prompt was not processed and to reconnect and retry.
- **Double disconnect**: Added an `intentional_stop` flag to `WslBridge` so that `stop()` / `interrupt()` — which kill the process themselves — suppress the duplicate "Disconnected unexpectedly" message that `handle_stdout`'s EOF path was also emitting.
- **Permission modal**: Fixed two cooperating reactivity bugs — `pendingPermissions` was mutated in-place (`.push()`), causing Svelte's derived-store chain to receive the same array reference and skip re-rendering; `PermissionModal.svelte` also used `$state()` (runes mode) where plain `let` is required for correct store-subscription reactivity.

## Test plan

- [ ] Unordered and ordered lists render with visible bullets and numbers in the chat terminal
- [ ] Completion sound plays once when a background tab finishes; switching back to that tab does not replay it
- [ ] Sounds for error, permission request, and task-start also play for background tabs and do not replay on tab switch
- [ ] Typing a prompt, switching tabs, and switching back restores the draft text
- [ ] Pressing Ctrl+C shows "keyboard shortcut (Ctrl+C)"; clicking the stop button shows "via stop button"
- [ ] If Claude exits mid-request, an error message appears prompting the user to resend
- [ ] Clicking stop or pressing Ctrl+C produces exactly one disconnect message (not two)
- [ ] When a tool requires permission, the permission modal appears and the user can approve or dismiss it

✨ This PR was created with help from Hikari~ 🌸

Reviewed-on: #173
Co-authored-by: Hikari <hikari@nhcarrigan.com>
Co-committed-by: Hikari <hikari@nhcarrigan.com>

src/lib/components/Markdown.svelte

@@ -281,10 +281,16 @@
     font-family: "JetBrains Mono", "Fira Code", monospace;
   }
 
-  .markdown-content :global(ul),
+  .markdown-content :global(ul) {
+    margin: 0.5em 0;
+    padding-left: 1.5em;
+    list-style-type: disc;
+  }
+
   .markdown-content :global(ol) {
     margin: 0.5em 0;
     padding-left: 1.5em;
+    list-style-type: decimal;
   }
 
   .markdown-content :global(li) {