chore: sdk regeneration 2026-04-29 (#703)

## Compatibility
- Restored legacy public aliases for renamed Agent History models and
params:
  - `AgentV1HistoryContent` -> `ConversationHistoryMessage`
  - `AgentV1HistoryFunctionCalls` -> `FunctionCallHistoryMessage`
- `AgentV1SettingsAgentContextMessagesItemContent` ->
`ConversationHistoryMessage`
- `AgentV1SettingsAgentContextMessagesItemFunctionCalls` ->
`FunctionCallHistoryMessage`
- Restored legacy create-key request aliases:
  - `CreateKeyV1RequestOne` -> `CreateKeyV1Request`
  - `CreateKeyV1RequestOneParams` -> `CreateKeyV1RequestParams`
- Added compatibility shim modules, package-level re-exports, runtime
tests, wire coverage, and targeted mypy coverage so existing imports and
typed call sites continue to work.
## Other Changes
- Re-applied socket-client manual patches:
  - broad `except Exception` handling across socket clients
- optional control-message defaults for `send_keep_alive`,
`send_finalize`, `send_close_stream`, `send_flush`, `send_clear`, and
`send_close`
  - `agent/v1` `_sanitize_numeric_types`
- `listen/v2` raw `send_configure(message: typing.Any)` shim and broader
response handling
- Added `AgentV1InjectAgentMessageBehavior`.
- Added `ListenV2LanguageHint` and `language_hint` support on Listen V2
connect clients.
- Updated regen docs and `.fernignore` to preserve the new compatibility
shims and regression tests in future regenerations.
## Validation
- `uv run pytest tests/custom/test_agent_history.py
tests/custom/test_compat_aliases.py
tests/wire/test_manage_v1_projects_keys.py`
- `uv run mypy --ignore-missing-imports
tests/typecheck/compat_aliases.py`
- `uv run pytest`

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