fix: address code-review findings from pass 1 + 2 (#8)

- Fix saveCourseToDB returning 0 on conflict by falling back to SELECT
- Fix inactive layouts showing 'Never played' when last_played exists
- Add .icon-btn.spinning to courses.css for refresh button feedback
- Remove duplicate .btn-primary from courses.css (use shared.css version)
- Tokenize rating tier colors into --rating-tier-{high,mid,low} CSS vars
- Convert var to const/let throughout courses.js
- Fix logger.error calls to use {err} object form (pino convention)
- Extract RATING_TIER_HIGH/MID constants in course-layouts.ejs scriptlet
- Remove dead href='#' View all link from courses.ejs (deferred)
- Pass total prop explicitly from course-table.ejs to course-cards.ejs
- Remove dead #search-results-info selector from mobile.css
- Remove redundant .replace(/"/g, '"') from data attributes in course-table.ejs

public/css/courses.css

@@ -78,26 +78,7 @@
 
 /* ── Buttons ──────────────────────────────────────── */
 
-.btn-primary {
-    background: var(--accent);
-    color: #fff;
-    border: 0;
-    height: 40px;
-    padding: 0 16px;
-    border-radius: var(--radius-sm);
-    font: 600 14px/1 var(--font-sans);
-    cursor: pointer;
-    white-space: nowrap;
-}
-
-.btn-primary:hover {
-    filter: brightness(1.05);
-}
-
-.btn-primary:disabled {
-    opacity: .6;
-    cursor: not-allowed;
-}
+/* .btn-primary is defined in shared.css — no override needed here */
 
 .btn-pill {
     padding: 6px 12px;
@@ -332,18 +313,18 @@
 }
 
 .chip-rating--green {
-    color: oklch(0.55 0.15 150);
-    background: color-mix(in oklch, oklch(0.55 0.15 150) 10%, transparent);
+    color: var(--rating-tier-high);
+    background: color-mix(in oklch, var(--rating-tier-high) 10%, transparent);
 }
 
 .chip-rating--amber {
-    color: oklch(0.55 0.12 100);
-    background: color-mix(in oklch, oklch(0.55 0.12 100) 10%, transparent);
+    color: var(--rating-tier-mid);
+    background: color-mix(in oklch, var(--rating-tier-mid) 10%, transparent);
 }
 
 .chip-rating--orange {
-    color: oklch(0.55 0.10 50);
-    background: color-mix(in oklch, oklch(0.55 0.10 50) 10%, transparent);
+    color: var(--rating-tier-low);
+    background: color-mix(in oklch, var(--rating-tier-low) 10%, transparent);
 }
 
 /* ── Inactive layouts collapsible ────────────────── */
@@ -386,6 +367,12 @@
     display: none;
 }
 
+/* ── Icon button spin state (keyframes defined in shared.css) ─── */
+
+.icon-btn.spinning {
+    animation: spin 0.8s linear infinite;
+}
+
 /* ── Tjing results ───────────────────────────────── */
 
 #tjing-results {

public/css/mobile.css

@@ -64,9 +64,6 @@
         display: none;
     }
 
-    /* Hide search result info text on courses (mobile has section-head) */
-    #search-results-info { display: none; }
-
     /* ── Container ──────────────────────────────────── */
 
     .container {

public/css/shared.css

@@ -34,6 +34,11 @@
     --font-sans: 'Plus Jakarta Sans', system-ui, sans-serif;
     --font-mono: 'JetBrains Mono', ui-monospace, monospace;
 
+    /* ── Rating tier tokens ───────────────────────── */
+    --rating-tier-high:   oklch(0.55 0.15 150);
+    --rating-tier-mid:    oklch(0.55 0.12 100);
+    --rating-tier-low:    oklch(0.55 0.10 50);
+
     /* legacy token aliases — remove as components migrate */
     --surface-0: var(--bg);
     --surface-1: var(--paper);