feat: (regen) diarization v2 batch GA, listen-provider dedup, think/models route fix (#714)

## Summary

Fern SDK regeneration on 2026-05-14, with manual patches re-applied.

### What's in this PR

1. **Generator output** (commit `7b085e8`, `fern-api[bot]`): new
generated files from the spec at `0052a02`. `pyproject.toml` bumped
`7.1.1` → `7.1.2`. Fern generator unchanged (`5.8.3`).
2. **Re-applied manual patches** (commit `2179f61`): 20 patched files,
none became obsolete after this regen.
3. **New listen-provider compat aliases** (same commit): the spec
deduplicated 5 PascalCase listen-provider types into 3 top-level
`DeepgramListenProvider*` names. To preserve backward compat over a
minor version bump, 10 hand-written alias files re-export from the new
names.

### Patch categories re-applied

- 4 socket clients (`agent/v1`, `listen/v1`, `listen/v2`, `speak/v1`):
broad `except Exception`, optional control-message defaults,
`_sanitize_numeric_types` (agent), `send_configure` raw shim +
`typing.Any` response (listen/v2).
- 6 agent-settings files: callable `AgentV1SettingsAgent(...)` wrapper,
broadened `agent` union (accepts wrapper + context + agent-id string),
legacy `messages=` validator + read-side property, legacy TypedDict
shapes.
- `agent_v1settings_audio_output.container`: kept as `Optional[str]`
instead of the enum alias.
- `core/query_encoder`: bool → lowercase coercion before `urlencode`.
- Wire test: restored `CreateKeyV1RequestOneParams` alias coverage.
- 7 package `__init__.py` files: legacy alias re-exports for
`CreateKeyV1RequestOne[Params]`, `AgentV1HistoryContent[Params]`,
`AgentV1HistoryFunctionCalls[Params]`, and
`AgentV1SettingsAgentContextMessagesItem*[Params]`.

### New compat aliases (listen-provider rename)

10 alias files added under `src/deepgram/agent/v1/{types,requests}/`,
each a one-line `from ....{types,requests}.deepgram_listen_provider_*
import DeepgramListenProvider*` re-export. All 10 added to `.fernignore`
as permanently frozen. `AGENTS.md` updated. Regression tests in
`tests/custom/test_compat_aliases.py` confirm each alias resolves to the
matching `DeepgramListenProvider*` target.

## Test plan

- [x] Fern regen output landed cleanly on the branch
- [x] All 20 `.bak` patches diffed against new gen; categorized via
subagent (all still needed)
- [x] Patches re-applied; new `DeepgramListenProvider*` exports kept
- [x] 10 listen-provider compat aliases created + re-exported from 4
`__init__.py` files
- [x] `.fernignore` reconciled (paths swapped back, 10 new entries
added)
- [x] All `.bak` files deleted
- [x] `ruff check src` clean
- [x] `mypy src` clean (801 files)
- [x] `pytest .` — 199 passed / 4 skipped (the skipped are
aiohttp/client autodetect cases, not regen-related)

---------

Co-authored-by: fern-api[bot] <115122769+fern-api[bot]@users.noreply.github.com>