rebrand: rename VoiceBox to TalkBox throughout codebase

- All 'voicebox'/'Voicebox'/'VOICEBOX' strings replaced with 'talkbox'/'TalkBox'/'TALKBOX'
- Port changed from 17493 to 17494 (avoids conflict with upstream VoiceBox)
- MCP tool namespace: voicebox.* -> talkbox.*
- App bundle ID: sh.voicebox.app -> com.talkbox.app
- Binary names: voicebox-server -> talkbox-server, voicebox-mcp -> talkbox-mcp
- Docker user/group: voicebox -> talkbox
- Database: voicebox.db -> talkbox.db
- Env vars: VOICEBOX_* -> TALKBOX_*
- Asset files renamed: voicebox-logo.* -> talkbox-logo.*, etc.
- External binaries in tauri.conf.json updated to talkbox-server/talkbox-mcp

RESPONSIBLE_USE.md

@@ -1,8 +1,8 @@
 # Responsible Use
 
-Voicebox is a local-first AI voice studio. It can clone voices from short audio samples, generate speech, and make AI agents speak through voice profiles. That capability is useful for accessibility, creative production, prototyping, game development, and personal tools, but it can also be misused.
+TalkBox is a local-first AI voice studio. It can clone voices from short audio samples, generate speech, and make AI agents speak through voice profiles. That capability is useful for accessibility, creative production, prototyping, game development, and personal tools, but it can also be misused.
 
-Voicebox does not and cannot independently verify who owns a voice sample. You are responsible for making sure you have the right to use every voice you clone, import, or generate with.
+TalkBox does not and cannot independently verify who owns a voice sample. You are responsible for making sure you have the right to use every voice you clone, import, or generate with.
 
 ## Allowed Uses
 
@@ -22,6 +22,6 @@ Voicebox does not and cannot independently verify who owns a voice sample. You a
 
 ## Disclosure And Compliance
 
-If you publish or distribute synthetic audio, disclose that it is AI-generated where required by law, platform policy, or audience expectations. Developers building products on top of Voicebox should treat consent records, disclosure, and jurisdiction-specific requirements as part of their own application design.
+If you publish or distribute synthetic audio, disclose that it is AI-generated where required by law, platform policy, or audience expectations. Developers building products on top of TalkBox should treat consent records, disclosure, and jurisdiction-specific requirements as part of their own application design.
 
-Voicebox runs locally to protect user privacy. That privacy model does not remove your responsibility to respect other people's voices.
+TalkBox runs locally to protect user privacy. That privacy model does not remove your responsibility to respect other people's voices.