Seed the vendor catalogue into SQL and add an optional AI course advisor

Course metadata: a scan now gives every course a course_meta row from the
downloader's sidecar JSON when the folder has one, else from catalog_courses
matched by the folder name the downloader would create (folderKeyFor, a port
of ine.py's sanitize_name). tools/build-catalog-seed.php turns the INE export
into seeds/ine_catalog.sql, an idempotent patch that creates its own table and
upserts by id, so it can be applied to the live server before or after the
code and re-run freely. Course pages show the blurb, difficulty, vendor and
tags; search matches tags and blurbs; Settings reports how each course got its
details. Against the live library 163 of 179 courses match.

Course advisor, off by default: api/advisor.php answers "which course should I
take to learn X / what comes before Y" with courses from the library, in
order, plus vendor courses not yet downloaded. includes/ai_client.php is a
small curl wrapper for any OpenAI-format chat endpoint (DeepSeek V4 Flash by
default, no composer); the prompt is a byte-stable catalogue of the library so
the provider's prefix cache covers it. Every course id the model returns is
validated server-side, a bad JSON reply gets one retry then a plain-text
fallback, and a per-user daily cap with token counts lives in
advisor_requests. With AI_ENABLED false the app makes no outbound requests
and the box does not appear; users can also hide it per browser.

Claude-Session: https://claude.ai/code/session_012enquL2RZdjy3D5AcKP5yx

api/library.php

@@ -10,6 +10,7 @@
 // GET api/library.php?view=settings            -> library paths, thresholds, progress summary
 require_once __DIR__ . '/../includes/auth.php';
 require_once __DIR__ . '/../includes/functions.php';
+require_once __DIR__ . '/../includes/advisor.php';   // aiEnabled() and the usage counters only
 
 header('Content-Type: application/json');
 $userId = requireLoginApi();
@@ -95,6 +96,7 @@ switch ($view) {
             ],
             'last_scan' => appMetaGet('last_scan_at'),
             'username'  => currentUsername(),
+            'advisor'   => aiEnabled(),
         ]);
         break;
 
@@ -179,6 +181,9 @@ switch ($view) {
             'rollup'      => $rollup,
             'progress'    => ['total' => $rollup['total'], 'completed' => $rollup['completed'],
                               'percent' => $rollup['percent']],
+            // What the catalogue or the sidecar file says about a course; null
+            // for sections, categories and courses that came from elsewhere.
+            'meta'        => $kind === 'course' ? courseMetaPublic(courseMeta((int)$folder['id'])) : null,
             'categories'  => $categories,
             'courses'     => $courses,
             'subfolders'  => $subfolders,
@@ -282,6 +287,14 @@ switch ($view) {
             'progress_courses'   => count($withSome),
             'courses'            => count($courses),
             'shelf_counts'       => $counts,
+            'catalog_courses'    => catalogCourseCount(),
+            'course_meta_counts' => json_decode((string)appMetaGet('course_meta_counts'), true) ?: null,
+            'advisor'            => [
+                'enabled'    => aiEnabled(),
+                'model'      => aiEnabled() ? aiModel() : null,
+                'used_today' => aiEnabled() ? advisorUsedToday($userId) : 0,
+                'limit'      => advisorLimit(),
+            ],
         ]);
         break;