Phase 3: dispatcher, transcript processor, text_dir resolution

- lib/dispatcher.py: one-shot dispatcher that scans acquired/<type>/
  for content+sidecar pairs and routes to registered processors
- lib/processors/transcript_processor.py: pre_flight() for transcripts
  (hash, dedupe, split into pages, register in DB, set text_dir)
- lib/utils.py: resolve_text_dir() helper for text_dir column fallback
- lib/enricher.py: use resolve_text_dir() instead of hardcoded path
- lib/embedder.py: use resolve_text_dir() instead of hardcoded path
- lib/processors/__init__.py, lib/acquisition/__init__.py: package inits

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

lib/dispatcher.py

@@ -0,0 +1,121 @@
+"""
+RECON Dispatcher
+
+Watches configured acquired/<subfolder>/ directories for content+sidecar pairs
+that have been stable (mtime unchanged) for the configured threshold, then
+hands them to the appropriate processor's pre_flight().
+
+Phase 3: importable one-shot dispatcher. Service-loop integration in Phase 5.
+"""
+import importlib
+import logging
+import os
+import time
+
+from .utils import get_config
+from .status import StatusDB
+
+logger = logging.getLogger("recon.dispatcher")
+
+
+def _load_processor(processor_name):
+    """Dynamically import a processor module from lib.processors."""
+    module_path = f"lib.processors.{processor_name}"
+    try:
+        return importlib.import_module(module_path)
+    except ImportError as e:
+        logger.error("Cannot load processor %s: %s", processor_name, e)
+        return None
+
+
+def _find_pairs(subfolder_path):
+    """Find content+sidecar pairs in a subfolder.
+
+    A pair is two files sharing a basename:
+      <basename>.txt  (or other content extension)
+      <basename>.meta.json  (sidecar)
+
+    Returns list of (content_path, meta_path, basename) tuples.
+    """
+    if not os.path.isdir(subfolder_path):
+        return []
+
+    files = set(os.listdir(subfolder_path))
+    pairs = []
+
+    for fname in sorted(files):
+        if fname.endswith('.meta.json'):
+            basename = fname[:-len('.meta.json')]
+            # Look for matching content file (try common extensions)
+            for ext in ['.txt', '.vtt', '.html', '.pdf']:
+                content_name = basename + ext
+                if content_name in files:
+                    pairs.append((
+                        os.path.join(subfolder_path, content_name),
+                        os.path.join(subfolder_path, fname),
+                        basename,
+                    ))
+                    break
+
+    return pairs
+
+
+def _is_stable(filepath, stability_seconds):
+    """Check if a file's mtime is older than stability_seconds ago."""
+    try:
+        mtime = os.path.getmtime(filepath)
+        return (time.time() - mtime) >= stability_seconds
+    except OSError:
+        return False
+
+
+def dispatch_once():
+    """One-shot dispatch: scan all configured acquired/ subfolders once.
+
+    Returns list of result dicts from processor pre_flight calls.
+    """
+    config = get_config()
+    pipeline_cfg = config.get('pipeline', {})
+    acquired_root = pipeline_cfg.get('acquired_root', '/opt/recon/data/acquired')
+    dispatch_map = pipeline_cfg.get('dispatch', {})
+    stability_seconds = pipeline_cfg.get('mtime_stability_seconds', 10)
+
+    db = StatusDB(config['paths']['db'])
+    results = []
+
+    for subfolder_name, processor_name in dispatch_map.items():
+        subfolder_path = os.path.join(acquired_root, subfolder_name)
+
+        processor = _load_processor(processor_name)
+        if processor is None:
+            continue
+
+        if not hasattr(processor, 'pre_flight'):
+            logger.error("Processor %s has no pre_flight function", processor_name)
+            continue
+
+        pairs = _find_pairs(subfolder_path)
+        if not pairs:
+            continue
+
+        for content_path, meta_path, basename in pairs:
+            # Both files must be stable
+            if not (_is_stable(content_path, stability_seconds) and
+                    _is_stable(meta_path, stability_seconds)):
+                logger.debug("Pair %s not yet stable, skipping", basename)
+                continue
+
+            logger.info("Dispatching %s/%s to %s", subfolder_name, basename, processor_name)
+            try:
+                result = processor.pre_flight(content_path, meta_path, db, config)
+                results.append(result)
+                logger.info("Result for %s: %s", basename, result.get('action', 'unknown'))
+            except Exception as e:
+                logger.error("Processor %s crashed on %s: %s", processor_name, basename, e)
+                results.append({
+                    'action': 'error',
+                    'error': str(e),
+                    'basename': basename,
+                })
+
+    return results