Phase 6: strip signature-restating docstrings; correct README/SETUP

- Collapsed Args:/Returns:/Raises: blocks that only restated the
  signature (364 lines): tektronix_base 48% -> ~20% doc density,
  helios_laser and uc480_camera likewise. Only docstrings whose entire
  body was those sections were touched.
- Preserved verbatim the comments that carry hardware knowledge the code
  can't express: uc480's USB split-transaction contention note (with its
  measured fps), the IS_ALLOW_STARTER_FW_UPLOAD segfault explanation, the
  QImage-copy rationale, and tektronix's NUMFRAMESACQuired warning.
- README: project structure, quick start, and every usage example now
  describe code that exists (they referenced hardware/bbd202.py,
  CoherentHOPSLaser, get_curve_binary, and 'python -m scanengine.app',
  none of which do). Added a headless-scan example and a read-a-scan-file
  example, since reuse without the GUI is the point of the refactor.
- SETUP: structure section defers to README instead of keeping a second
  stale copy; documents the vendored uEye SDK and the Genesis quarantine.
- ruff is now clean repo-wide: fixed the remaining raise-from, unused
  loop variables, placeholder f-strings, and a non-strict zip; the
  widget-layout semicolon idiom is an explicit config ignore rather than
  22 standing warnings.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>

hardware/pybbd202/apt_messages.py

@@ -280,8 +280,7 @@ class APTProtocol():
                 raise ValueError(f"No data fields have been defined for {msg_spec['name']}!")
             
             unpacked_payload = struct.unpack(fmt_string, payload)
-            data = {field: value for field, value in zip(data_fields,
-                                                         unpacked_payload)}
+            data = dict(zip(data_fields, unpacked_payload, strict=True))
             data['destination'] = dest
             data['source'] = src
 

hardware/pybbd202/bbd20x.py

@@ -344,7 +344,7 @@ class ThorlabsServoDriver():
             power up. Default timeout is 60s, but 20-30s is fine as well if
             you're in that much of a hurry.
         '''
-        ch = self._channel_for(axis)
+        self._channel_for(axis)   # validate the axis address
 
         self.send_and_wait(0x0443, timeout=timeout, retries=0, chan_ident=1,
                            destination=axis, source=0x01)