Support Remote browser and media keys and connection history UI

Accept the eighteen browser, volume, media and launch identities in the input vocabulary and both SDKs. Exercise media-key capture on the private Xorg harness, and permit only the new remember-host checkbox in the connection form integration test.

Validated: affected-package race tests, Tentacles make check, private native_remote_input.py and native_remote_keys.py. Physical input, live peer interoperability, speech and Braille acceptance remain pending.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

docs/tentacle-remote-keyboard.md

@@ -29,6 +29,12 @@ allowlist matches the external mapper's canonical subset:
 - Left/right Shift, Control, Alt and Super; Menu, lock keys, Pause and Print.
 - Backspace, Tab, Return, Escape and Space; main navigation, Insert and Delete.
 - Keypad Enter, navigation, Begin, Insert, Delete and arithmetic/separator keys.
+- Eighteen browser, volume, media and launch keys (`XF86Back`, `XF86Forward`,
+  `XF86Reload`, `XF86Stop`, `XF86Search`, `XF86Favorites`, `XF86HomePage`,
+  `XF86AudioMute`, `XF86AudioLowerVolume`, `XF86AudioRaiseVolume`,
+  `XF86AudioNext`, `XF86AudioPrev`, `XF86AudioStop`, `XF86AudioPlay`,
+  `XF86Mail`, `XF86AudioMedia`, `XF86MyComputer`, `XF86Calculator`), matching
+  Windows VK 0xA6–0xB7. Other XF86 keys, such as power and eject, stay unsupported.
 - The eleven explicit punctuation identities supported by the external US
   profile. The owner must resolve the destination layout; this does not grant
   permission to guess a matching physical key or change the global keymap.