readme: add build & deploy section (server docker, android APK, gitea release)

README.md

@@ -156,6 +156,62 @@ synq/
 5. add history screen and resend handling.
 6. polish launch speed and widget/share-target only after core path works.
 
+## build & deploy
+
+### server (docker)
+
+```bash
+# build
+docker build -t synq-server ./server
+
+# run (replace paths and token as needed)
+docker run -d --name synq --restart=unless-stopped \
+  -p 8765:8765 \
+  -v /mnt/user/synq/data:/data \
+  synq-server
+```
+
+the server generates a random token on first start and logs it prominently. copy it into the android app settings. to use a fixed token instead, pass `-e PHONE_CAPTURE_TOKEN=yourtoken`.
+
+to rebuild after a `git pull`:
+
+```bash
+git pull
+docker build -t synq-server ./server
+docker stop synq && docker rm synq
+# re-run the docker run command above
+```
+
+### android
+
+open `android/` in Android Studio and hit **Sync**. then either:
+
+- **run on device/emulator directly** from Android Studio (▶), or
+- **build a release APK** from the terminal:
+
+```bash
+cd android
+./gradlew assembleRelease
+# output: app/build/outputs/apk/release/app-release-unsigned.apk
+```
+
+sideload to a connected device:
+
+```bash
+adb install app/build/outputs/apk/release/app-release-unsigned.apk
+```
+
+### releasing on gitea
+
+tag the commit and push the tag:
+
+```bash
+git tag v1.0.0
+git push gitea v1.0.0
+```
+
+then go to **Releases → New Release** in the Gitea UI, pick the tag, and drag the APK into the assets box. anyone on the LAN can download it from there.
+
 ## backup
 
 ### what to back up