fix(kotlin): stop deprecations pointing at deprecated replacements

[ayaangazali]

What is wrong

Six @Deprecated messages on the legacy extension surface tell the caller to move to a namespace method that is itself deprecated, so following the advice lands them on a second deprecation:

legacy extension	current advice	that target's own annotation
unloadModel	models.unload(category)	@Deprecated("Use unloadAll(category).")
stopSynthesis	tts.stop()	@Deprecated("Use the SpeechHandle returned by speak().")
stopSpeaking	tts.stop()	same
streamVAD	vad.detectStream(audio, options)	@Deprecated("Use vad.openStream(format, options).")
resetVAD	vad.detectStream	same
transcribeStream	stt.transcribeStream(audio, options)	@Deprecated("Use stt.openStream(format, options).")

The IDE shows the strikethrough and the message, the caller migrates, and gets struck through again. ReplaceWith is not involved in any of these, so nothing auto-applies, but the written guidance is a dead end and no gate covers it. check_deprecated_surfaces.sh tracks which deprecated surfaces exist against an allowlist; it does not check that a deprecation's target is supported.

What this changes

Each message now names the replacement the namespace's own annotation points at, so one hop reaches a supported API:

• models.unloadAll(category)
• interrupt() on the SpeechHandle returned by tts.speak()
• vad.openStream(format, options), and close() on the VadStream it returns for the reset case
• stt.openStream(format, options)

I took each target from the deprecated namespace method's own annotation rather than picking one, and confirmed the members exist: ModelsNamespace.unloadAll (:266), TtsNamespace.speak (:60) returning SpeechHandle with interrupt() (Results.kt:252), SttNamespace.openStream (:189), and VadStream.close() (Results.kt:315).

Message strings only. No signature, body, or ReplaceWith target changes, so this cannot alter behaviour.

How I found them

Collected the deprecated methods declared inside public/api/*Namespace.kt, then looked for any @Deprecated message elsewhere naming <namespace>.<method> for that set. Six hits, four files. After the change the same scan reports zero.

Worth noting the scan produced 31 raw hits at first and 25 were false positives, because a deprecated extension and the live namespace method often share a simple name (generate, rerank, diarize). Those messages are correct and I left them alone; only the six above name a target that really is deprecated.

Verification

• ./gradlew :compileDebugKotlin --rerun-tasks -x :buildLocalJniLibs -x :downloadJniLibs -x :syncAndroidRuntimeLibs -Prunanywhere.useLocalNatives=false: BUILD SUCCESSFUL
• ./gradlew ktlintMainSourceSetCheck: clean
• git status shows only the four source files; the codegen the Gradle build runs left nothing behind

No test added: these are annotation strings, and a test asserting the text of a deprecation message would pin prose rather than behaviour.

[Copilot]

Copilot was unable to review this pull request because the user who requested the review has reached their quota limit.

[ayaangazali]

Heads up on the red python-linux (3.9) and (3.12) cells here: they are not from this diff.

Both are red on main too, at b2d2ff6d (run 32011099890), with "The job has exceeded the maximum execution time of 1h30m0s". The job hangs inside auditwheel repair because the prep step's ln -sf libonnxruntime.so lib/libonnxruntime.so.1 overwrites the middle link of the chain the new RunAnywhere desktop prebuilt ships, turning libonnxruntime.so and libonnxruntime.so.1 into a symlink loop.

I opened #736 with the evidence and a one-line guard. Nothing to do on this PR; every other check here is green.