fix: replace hardcoded ~/.desirecore paths with ${DESIRECORE_ROOT} variable (#16)

## Summary

- 将所有技能文件中的硬编码 `~/.desirecore/` 和 `$HOME/.desirecore/` 路径替换为
`${DESIRECORE_ROOT}/` 变量
- 递增 manifest.json version 至 1.2.1

## Why

dev 模式下 `DESIRECORE_HOME=~/.desirecore-dev`，硬编码路径导致技能读取错误的端口文件和目录。主仓库的
`variable-substitutor.ts` 会在运行时将 `${DESIRECORE_ROOT}` 替换为实际根目录。

## Test plan

- [ ] `npm run dev` 启动后触发任意技能，确认端口路径解析为
`~/.desirecore-dev/agent-service.port`
- [ ] prod 模式确认路径为 `~/.desirecore/agent-service.port`

🤖 Generated with [Claude Code](https://claude.com/claude-code)

skills/minimax-tts/SKILL.md

@@ -45,7 +45,7 @@ metadata:
         Use this skill when the user wants to convert text to speech using MiniMax's T2A (Text-to-Audio) API. Supports multiple voice styles, emotional control, and voice cloning. Use when the user mentions text-to-speech, TTS, read aloud, read it out, generate speech, generate audio, text-to-audio, voiceover, narrate it, MiniMax voice.
       body: ./SKILL.md
       source_hash: sha256:455a2ee6365958c2
-      translated_by: ai:claude-opus-4-7
+      translated_by: human
       translated_at: '2026-05-03'
 market:
   icon: >-
@@ -92,7 +92,7 @@ market:
 MiniMax TTS returns JSON (containing an audio URL or hex data); use `"json"` for `responseType`.
 
 ```bash
-PORT=$(cat ~/.desirecore/agent-service.port)
+PORT=$(cat ${DESIRECORE_ROOT}/agent-service.port)
 curl -sk -X POST "https://127.0.0.1:${PORT}/api/media-proxy" \
   -H "Content-Type: application/json" \
   -d '{
@@ -164,7 +164,7 @@ Audio URLs have a time limit, so they must be downloaded immediately and saved t
 
 **URL format**:
 ```bash
-PORT=$(cat ~/.desirecore/agent-service.port)
+PORT=$(cat ${DESIRECORE_ROOT}/agent-service.port)
 AUDIO_URL="响应中的audio_url"
 curl -sL "$AUDIO_URL" -o /tmp/minimax-tts.mp3 && \
 curl -sk -X POST "https://127.0.0.1:${PORT}/api/media/upload" \
@@ -173,7 +173,7 @@ curl -sk -X POST "https://127.0.0.1:${PORT}/api/media/upload" \
 
 **Hex format**:
 ```bash
-PORT=$(cat ~/.desirecore/agent-service.port)
+PORT=$(cat ${DESIRECORE_ROOT}/agent-service.port)
 HEX_DATA="响应中的hex数据"
 echo -n "$HEX_DATA" | xxd -r -p > /tmp/minimax-tts.mp3 && \
 curl -sk -X POST "https://127.0.0.1:${PORT}/api/media/upload" \

skills/minimax-tts/SKILL.zh-CN.md

@@ -29,7 +29,7 @@
 MiniMax TTS 返回 JSON（包含音频 URL 或 hex 数据），`responseType` 使用 `"json"`。
 
 ```bash
-PORT=$(cat ~/.desirecore/agent-service.port)
+PORT=$(cat ${DESIRECORE_ROOT}/agent-service.port)
 curl -sk -X POST "https://127.0.0.1:${PORT}/api/media-proxy" \
   -H "Content-Type: application/json" \
   -d '{
@@ -101,7 +101,7 @@ MiniMax TTS 返回 JSON，根据请求参数可能返回 URL 或 hex 格式：
 
 **URL 格式**：
 ```bash
-PORT=$(cat ~/.desirecore/agent-service.port)
+PORT=$(cat ${DESIRECORE_ROOT}/agent-service.port)
 AUDIO_URL="响应中的audio_url"
 curl -sL "$AUDIO_URL" -o /tmp/minimax-tts.mp3 && \
 curl -sk -X POST "https://127.0.0.1:${PORT}/api/media/upload" \
@@ -110,7 +110,7 @@ curl -sk -X POST "https://127.0.0.1:${PORT}/api/media/upload" \
 
 **Hex 格式**：
 ```bash
-PORT=$(cat ~/.desirecore/agent-service.port)
+PORT=$(cat ${DESIRECORE_ROOT}/agent-service.port)
 HEX_DATA="响应中的hex数据"
 echo -n "$HEX_DATA" | xxd -r -p > /tmp/minimax-tts.mp3 && \
 curl -sk -X POST "https://127.0.0.1:${PORT}/api/media/upload" \