docs: update documentation and devlog for TalkBox fork and rebrand

- Updated CHANGELOG.md: added fork, rebrand, port isolation, and DCP workflow entries to Unreleased
- Updated project record: set TalkBox project identity, summary, and architecture tags
- Updated devlog index: set TalkBox devlog title and summary
- Added devlog entry 'fork-and-rebrand': initial fork, rebrand, port migration, and devlog workflow

.labyricorn/devlog/contents.lr

@@ -2,6 +2,6 @@ _model: devlog
 ---
 schema_version: 1
 ---
-title: Labyricorn Project Template development log
+title: TalkBox development log
 ---
-summary: Milestones and development log entries for the Labyricorn project template.
+summary: Milestones and development log entries for TalkBox, the local-first AI voice studio.

.labyricorn/devlog/fork-and-rebrand/contents.lr

@@ -0,0 +1,35 @@
+_model: devlog-entry
+---
+schema_version: 1
+---
+title: Forking and rebranding VoiceBox into TalkBox
+---
+date: 2026-08-24
+---
+author: Labyricorn
+---
+summary: Initial fork from upstream VoiceBox with a full codebase rebrand to TalkBox, updated port and bundle IDs, and integration of the .DCP documentation and publishing workflow.
+---
+tags: fork, rebrand, tts, mcp, devlog, release
+---
+source_commit: 7ad90d93a7b7fdfe97725bfc83bda228d266c657
+---
+body:
+
+TalkBox has been established as an independent fork of [VoiceBox](https://git.labyricorn.com/Labyricorn/voicebox) to serve as our customized local-first AI voice studio and MCP voice bridge.
+
+### Summary of Changes
+
+1. **Codebase Rebranding**:
+   - Replaced all naming across 205 files spanning frontend components (React/TypeScript), desktop harness (Tauri v2 / Rust), backend services (FastAPI/Python), documentation, and build scripts.
+   - Renamed core sidecar binaries to `talkbox-server` and `talkbox-mcp`.
+   - Updated database files to `talkbox.db` and environment variables to the `TALKBOX_*` namespace.
+
+2. **Network and Service Isolation**:
+   - Migrated the default backend and MCP HTTP port from `17493` to `17494` to enable concurrent execution alongside upstream VoiceBox instances without port collisions.
+   - Standardized the MCP tools namespace to `talkbox.speak`, `talkbox.transcribe`, `talkbox.list_captures`, and `talkbox.list_profiles`.
+   - Updated the client identifier header to `X-TalkBox-Client-Id`.
+
+3. **Labyricorn Publishing & Devlog Integration**:
+   - Restored and configured the repository's `.labyricorn/` publishing records and `devlog_editor.py` validator.
+   - Introduced the `.DCP` (Document, Commit, Push) shorthand command and automated skill workflow for continuous devlog maintenance and release tracking.