feat: regenerate Python SDK (agent/tts namespaces) + bundled realtime connect layer

[lspeechify]

Regenerates the Python SDK from the updated API spec and adds a hand-written realtime connect layer.

What's in here

1. Regenerated client (product namespaces). Generated from the spec with per-product SDK namespaces, so the surface is:

• client.tts.audio.*, client.tts.voices.*
• client.agent.* (agent CRUD, flattened) + client.agent.{conversations,tools,knowledge_bases,tests,...}

(Previously everything was nested under client.tts.*.) HTTP wire is unchanged — this is the generated SDK method surface only.

2. speechify.realtime connect layer (hand-written, .fernignore'd). Opens a realtime voice-agent session from the { url, token } returned by client.agent.create_conversation(...) / create_session(...):

from speechify import Speechify, realtime

client = Speechify(token="...")
conv = client.agent.create_conversation(agent_id)
session = await realtime.connect_conversation(conv)   # connect, observe events, disconnect

Public surface is vendor-neutral (connect, connect_conversation, RealtimeSession, events participant_joined / audio / disconnected); the realtime transport client is an internal implementation detail. The module lives under src/speechify/realtime/ and is listed in .fernignore, so regeneration never clobbers it.

3. Dependency. Adds the realtime client as a dependency scoped with a Python marker — python = "^3.8" (base SDK) stays, the realtime client is only pulled on >=3.9 (it requires 3.9+). Configured via extra_dependencies in the upstream fern/generators.yml.

Notes

• Generated on top of the spec's namespace change (api PR #1629). Draft pending that landing + review.
• Verified locally: generation + poetry install solve, import smoke, and a live create→connect→disconnect against prod.

🤖 Generated with Claude Code

[linear-code]

DRG-31