Replace hardcoded config and directory scan with YAML config and explicit clip list

- config.py constants -> config/config.yaml (user-editable, git-ignored)
- Questions and defaults now defined in the YAML, including per-question defaults
- ClipSelector no longer scans the data dir; reads a user-provided clips.txt instead
- Removed --daily / --time / --skip-existing-day args
- video_loader now samples frames evenly across the full clip
- pyyaml added as a dependency

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

src/river_annotation_tool/annotator.py

@@ -18,7 +18,7 @@ from PySide6.QtWidgets import (
 )
 
 from .clip_selector import ClipSelector
-from .config import DEFAULTS, QUESTIONS, Config
+from .config import AppConfig
 from .mask_canvas import MaskCanvas
 from .video_loader import load_frames
 
@@ -26,25 +26,20 @@ from .video_loader import load_frames
 class Annotator(QMainWindow):
     def __init__(
         self,
-        data_dir: Path,
-        out_dir: Path,
+        config: AppConfig,
         clip: str = None,
-        target_time: str = None,
-        daily: bool = False,
         extras: bool = False,
-        skip_existing_day: bool = False,
     ):
         super().__init__()
 
-        self.out_dir = Path(out_dir)
+        self.cfg = config
+        self.out_dir = Path(config.out_dir)
         self.extras = extras
 
         self.selector = ClipSelector(
-            data_dir=Path(data_dir),
+            data_dir=Path(config.data_dir),
             out_dir=self.out_dir,
-            target_time=target_time,
-            daily=daily,
-            skip_existing_day=skip_existing_day,
+            clips_file=Path(config.clips_file),
         )
 
         self.setWindowTitle("River Annotator")
@@ -53,10 +48,13 @@ class Annotator(QMainWindow):
         self._init_timer()
 
     # ── clip loading ───────────────────────────────────────────────
-    def _load_clip(self, specific: str = None, next_day: bool = False):
-        self.filename = self.selector.next(specific=specific, next_day=next_day)
+    def _load_clip(self, specific: str = None):
+        self.filename = self.selector.next(specific=specific)
         self.frames, self.fps, self.dh, self.dw, self.h, self.w = load_frames(
-            self.filename, Config.MAX_FRAMES
+            self.filename,
+            self.cfg.max_frames,
+            self.cfg.display_max,
+            self.cfg.fps_fallback,
         )
         self._pending_answers = self._read_saved_answers()
 
@@ -135,23 +133,22 @@ class Annotator(QMainWindow):
 
     def _build_question_panel(self) -> QVBoxLayout:
         vbox = QVBoxLayout()
-        for section, qs in QUESTIONS:
+        for section, qs in self.cfg.get_questions():
             group = QGroupBox(section)
             gvbox = QVBoxLayout()
-            for key, label, options in qs:
+            for key, label, options, default in qs:
                 gvbox.addWidget(QLabel(label))
                 btn_group = QButtonGroup(self)
                 row = QHBoxLayout()
                 buttons = []
-                default_value = DEFAULTS.get(key)
                 for opt in options:
                     btn = QRadioButton(opt)
                     btn_group.addButton(btn)
                     row.addWidget(btn)
                     buttons.append(btn)
-                    if default_value == opt:
+                    if default == opt:
                         btn.setChecked(True)
-                if default_value is None and buttons:
+                if default is None and buttons:
                     buttons[-1].setChecked(True)
                 self.q_widgets[key] = (btn_group, buttons, options)
                 gvbox.addLayout(row)
@@ -246,8 +243,8 @@ class Annotator(QMainWindow):
         if answers:
             self._set_answers(answers)
 
-    def _advance_clip(self, next_day: bool):
-        self._load_clip(next_day=next_day)
+    def _advance_clip(self):
+        self._load_clip()
         self.frame_i = 0
         self.mc.load_clip(
             self.frames,
@@ -262,7 +259,7 @@ class Annotator(QMainWindow):
 
     def next_clip(self):
         self.save()
-        self._advance_clip(next_day=self.selector.daily)
+        self._advance_clip()
 
     def skip_clip(self):
-        self._advance_clip(next_day=self.selector.daily)
+        self._advance_clip()