fix: register bundled TTS providers and route overrides correctly (#62846) (thanks @stainlu)

* fix(microsoft,elevenlabs): add enabledByDefault so speech providers register at runtime

* fix(tts): route generic directive tokens to the explicitly declared provider

Addresses the P2 Codex review on #62846 that flagged auto-enabling
ElevenLabs as a product regression for MiniMax users. Both providers
claim the generic `speed` token, and parseTtsDirectives walked
providers in autoSelectOrder with first-match-wins, so inputs like
`[[tts:provider=minimax speed=1.2]]` silently routed speed to
providerOverrides.elevenlabs once elevenlabs participated in every
parse pass.

The parser now pre-scans for `provider=` (honoring legacy last-wins
semantics) and routes generic tokens with the declared provider tried
first, falling back to autoSelectOrder when it doesn't handle the key.
Token order inside the directive no longer matters: `speed=1.2` before
or after `provider=minimax` both resolve to MiniMax.

Adds a regression test suite covering the exact ElevenLabs/MiniMax
speed collision plus fallback, mixed-token, last-wins, and
allowProvider-disabled cases. parseTtsDirectives had no prior test
coverage.

* fix(tts): prefer active provider for generic directives

* fix: register bundled TTS providers safely (#62846) (thanks @stainlu)

* fix: use exported TTS SDK seam (#62846) (thanks @stainlu)

---------

Co-authored-by: Ayaan Zaidi <hi@obviy.us>

extensions/microsoft/openclaw.plugin.json

@@ -1,5 +1,6 @@
 {
   "id": "microsoft",
+  "enabledByDefault": true,
   "contracts": {
     "speechProviders": ["microsoft"]
   },