Initial commit: boarding pass to AirTrail pipeline

Photograph/screenshot a boarding pass, decode its BCBP barcode (PDF417/
Aztec/QR/DataMatrix), fetch the historical flight track from FlightAware
the day after the flight, stage it for review, and write it into AirTrail
via its REST API on approval. ntfy notifications carry signed
Approve/Deny/Investigate actions.

templates/upload.html

@@ -0,0 +1,17 @@
+{% extends "base.html" %}
+{% block title %}Upload — Boarding Pass{% endblock %}
+{% block content %}
+<h1>Upload a boarding pass</h1>
+<p class="muted">Upload a photo or screenshot showing the barcode on your boarding pass.
+It'll be decoded, queued, and tracked automatically the day after your flight.</p>
+
+{% if error %}<div class="alert alert-danger">{{ error }}</div>{% endif %}
+
+<form method="post" enctype="multipart/form-data" class="card upload-form">
+  <label for="photo" class="upload-drop">
+    <span>Tap to choose a photo or screenshot</span>
+    <input type="file" id="photo" name="photo" accept="image/*" required>
+  </label>
+  <button type="submit" class="btn btn-primary">Upload &amp; decode</button>
+</form>
+{% endblock %}