Delete commented-out code that forced pypylon to create emulation virtual cameras (PYLON_CAMEMU), which was only intended for testing and should not be enabled for release. Also remove an extraneous blank line to tidy up the file.

Introduce a TriggerUiProfile dataclass and trigger_ui_profile_for_backend() to drive dialog presentation per backend. Replace free-text source field with an editable QComboBox providing backend suggestions and defaults. Add profile-driven visibility/enabling for input, master, software and strobe/line output fields, plus helper methods to manage form rows and combo text. Only include strobe-related payload fields when the backend profile exposes them. Misc: expand info/help text, show backend in group title, increase dialog min-width, refine tooltips, and improve model↔UI mapping and payload construction.

Previously the default trigger configuration was only applied for backend 'gentl' and always stored under the 'gentl' properties key. This change treats the backend name dynamically (accepting both 'gentl' and 'basler'), and stores the default trigger settings under the actual backend key in cam.properties. Also preserves behavior when cam.properties or the backend namespace is not a dict.

Reduce log flooding when waiting for hardware triggers by adding throttled logging.

Changes in dlclivegui/services/multi_camera_controller.py:
- Import time.
- Add a new _log_interval_while_waiting_for_trigger_s attribute to SingleCameraWorker.
- Replace the direct LOGGER.debug call for expected trigger wait timeouts with a call to _log_trigger_wait_throttled.
- Implement _log_trigger_wait_throttled to suppress repeated timeout messages, emit a consolidated debug message, and report how many repeated logs were suppressed.

This prevents high-frequency expected poll-timeout logs (common in trigger-waiting modes) from overwhelming the logs.

Extend the test conftest FakePylon to better emulate pypylon: add FakePylonTimeoutException, richer _Feature (symbolics, min/max/inc, read/write checks, call tracking), _EnumEntry, expanded _DeviceInfo, GrabResult.release tracking, and a more complete InstantCamera (timeouts, software trigger, trigger/line features, buffer and grab controls, test knobs). Reset the fake factory and provide default fake devices and a basler_settings_factory fixture. Patch the basler SDK fixture to use FakePylon. Add new test suite tests/cameras/backends/test_basler_backend.py covering lifecycle (open/read/close, fast-start, idempotent close), discovery/rebind, resolution/exposure/gain/fps handling, and comprehensive trigger behavior (follower/master/software/external) to validate backend logic.

Add throttled logging for hardware-trigger wait timeouts in SingleCameraWorker to avoid noisy repeated timeout messages. Introduce _trigger_wait_log_interval, _last_trigger_wait_log and _trigger_wait_suppressed_count and move _log_trigger_wait_throttled into the worker; remove the duplicate implementation from MultiCameraController. Also mark the Basler software-trigger test as xfail because software trigger support is not implemented yet.

Integrates optional WorkerTimingStats into the Basler camera backend and refactors FPS handling and frame retrieval. Adds a _configure_frame_rate() helper to centralize AcquisitionFrameRate enabling, setting and readbacks (logs many related nodes and records actual_fps). Initializes a WorkerTimingStats instance (controlled by SINGLE_CAMERA_WORKER_DO_LOG_TIMING) and wraps RetrieveResult/convert/get array/release steps with timing measurements, improved error handling, proper grab_result release on exceptions, and frame counting/logging. Overall improves observability and robustness when setting frame rates and reading frames from Basler cameras.

Refactors `MultiCameraController.stop()` to track a dedicated stopping state and finalize shutdown only after all camera threads are actually stopped. It now delays `all_stopped` emission until cleanup is truly complete, keeps references to threads that refuse to terminate, and avoids the previous premature "stopped" state. The main window now explicitly calls `stop(wait=True)` during camera/project shutdown so UI transitions block until camera teardown is done.

Import `genicam` alongside `pylon` and add a helper to detect `genicam.TimeoutException` safely. The hardware-trigger timeout path now converts exceptions to `TimeoutError` only for true SDK timeout exceptions, avoiding incorrect timeout handling for unrelated grab failures.

Tightens controller start/stop state handling to prevent unsafe restarts while shutdown is in progress, and finalizes shutdown only after all camera threads actually exit. Cleanup now resets runtime state consistently, `all_stopped` emission is guarded against duplicates, and stop requests only fan out to workers when actively running. Camera stop handling was also refined so full initialization failure and last-camera runtime shutdown both transition into the same safe finalization path, with clearer logging around incomplete shutdowns.