feat: Refactored channel header into grouped control sections (Monitori…

- "src/frontend/src/pages/ChannelDetail.tsx"

GSD-Task: S03/T02

src/frontend/src/pages/ChannelDetail.tsx

@@ -1,4 +1,4 @@
-import { useState, useEffect, useMemo, useCallback } from 'react';
+import { useState, useEffect, useMemo, useCallback, useRef } from 'react';
 import { useParams, useNavigate, Link } from 'react-router-dom';
 import {
   ArrowLeft,
@@ -7,6 +7,7 @@ import {
   CheckCircle,
   ChevronDown,
   ChevronRight,
+  ChevronUp,
   Download,
   ExternalLink,
   Film,
@@ -17,7 +18,6 @@ import {
   Music,
   RefreshCw,
   Save,
-  Search,
   Trash2,
 } from 'lucide-react';
 import { useChannel, useUpdateChannel, useDeleteChannel, useScanChannel, useSetMonitoringMode, useScanStatus } from '../api/hooks/useChannels';
@@ -151,6 +151,24 @@ export function ChannelDetail() {
   const [checkIntervalSaved, setCheckIntervalSaved] = useState(false);
   const { toast } = useToast();
 
+  // ── Collapsible header ──
+  const headerRef = useRef<HTMLDivElement>(null);
+  const [isHeaderCollapsed, setIsHeaderCollapsed] = useState(false);
+
+  useEffect(() => {
+    const el = headerRef.current;
+    if (!el) return;
+    const observer = new IntersectionObserver(
+      ([entry]) => {
+        // Collapse when the header is mostly out of view
+        setIsHeaderCollapsed(!entry.isIntersecting);
+      },
+      { threshold: 0, rootMargin: '-60px 0px 0px 0px' },
+    );
+    observer.observe(el);
+    return () => observer.disconnect();
+  }, []);
+
   // Sync local check interval from channel data
   useEffect(() => {
     if (channel?.checkInterval != null) {
@@ -774,248 +792,347 @@ export function ChannelDetail() {
         <ArrowLeft size={14} /> Back to Channels
       </Link>
 
-      {/* Channel header */}
+      {/* Compact sticky bar — visible when full header scrolls out of view */}
       <div
         style={{
+          position: 'sticky',
+          top: 0,
+          zIndex: 100,
+          transform: isHeaderCollapsed ? 'translateY(0)' : 'translateY(-100%)',
+          opacity: isHeaderCollapsed ? 1 : 0,
+          pointerEvents: isHeaderCollapsed ? 'auto' : 'none',
+          transition: 'transform 0.25s ease, opacity 0.2s ease',
           display: 'flex',
-          gap: 'var(--space-5)',
-          padding: 'var(--space-5)',
+          alignItems: 'center',
+          gap: 'var(--space-3)',
+          padding: 'var(--space-2) var(--space-4)',
           backgroundColor: 'var(--bg-card)',
-          borderRadius: 'var(--radius-xl)',
-          border: '1px solid var(--border)',
-          marginBottom: 'var(--space-6)',
-          alignItems: 'flex-start',
+          borderBottom: '1px solid var(--border)',
+          boxShadow: isHeaderCollapsed ? '0 2px 8px rgba(0,0,0,0.15)' : 'none',
           flexWrap: 'wrap',
         }}
+        aria-hidden={!isHeaderCollapsed}
       >
-        {/* Avatar */}
+        {/* Identity — compact */}
         <img
           src={
             channel.imageUrl ||
-            `https://ui-avatars.com/api/?name=${encodeURIComponent(channel.name)}&background=242731&color=e1e2e6&size=80`
+            `https://ui-avatars.com/api/?name=${encodeURIComponent(channel.name)}&background=242731&color=e1e2e6&size=32`
           }
-          alt={`${channel.name} avatar`}
+          alt=""
           style={{
-            width: 80,
-            height: 80,
+            width: 28,
+            height: 28,
             borderRadius: '50%',
             objectFit: 'cover',
             backgroundColor: 'var(--bg-hover)',
             flexShrink: 0,
           }}
         />
+        <span style={{ fontWeight: 600, fontSize: 'var(--font-size-sm)', color: 'var(--text-primary)', whiteSpace: 'nowrap' }}>
+          {channel.name}
+        </span>
+        <PlatformBadge platform={channel.platform} />
 
-        {/* Info */}
-        <div style={{ flex: 1, minWidth: 200 }}>
-          <div style={{ display: 'flex', alignItems: 'center', gap: 'var(--space-3)', flexWrap: 'wrap' }}>
-            <h1
+        <div style={{ width: 1, height: 20, backgroundColor: 'var(--border)', flexShrink: 0 }} />
+
+        {/* Key actions — compact */}
+        <select
+          value={channel.monitoringMode}
+          onChange={handleMonitoringModeChange}
+          disabled={setMonitoringMode.isPending}
+          aria-label="Monitoring mode"
+          style={{ padding: '4px 8px', borderRadius: 'var(--radius-md)', fontSize: 'var(--font-size-xs)', minWidth: 110 }}
+        >
+          {MONITORING_MODE_OPTIONS.map((opt) => (
+            <option key={opt.value} value={opt.value}>{opt.label}</option>
+          ))}
+        </select>
+
+        <button
+          onClick={handleScan}
+          disabled={scanChannel.isPending || scanInProgress}
+          title={scanInProgress ? 'Scan in progress…' : 'Refresh & Scan'}
+          className="btn btn-ghost"
+          style={{ padding: '4px 10px', fontSize: 'var(--font-size-xs)', opacity: (scanChannel.isPending || scanInProgress) ? 0.6 : 1 }}
+        >
+          {(scanChannel.isPending || scanInProgress) ? (
+            <Loader size={12} style={{ animation: 'spin 1s linear infinite' }} />
+          ) : (
+            <RefreshCw size={12} />
+          )}
+          {scanInProgress ? 'Scanning…' : 'Scan'}
+        </button>
+
+        <button
+          onClick={handleCollect}
+          disabled={collectMonitored.isPending}
+          title="Collect Monitored"
+          className="btn btn-ghost"
+          style={{ padding: '4px 10px', fontSize: 'var(--font-size-xs)', opacity: collectMonitored.isPending ? 0.6 : 1 }}
+        >
+          {collectMonitored.isPending ? (
+            <Loader size={12} style={{ animation: 'spin 1s linear infinite' }} />
+          ) : (
+            <Download size={12} />
+          )}
+          Collect
+        </button>
+
+        <div style={{ flex: 1 }} />
+
+        {/* Scroll-to-top to reveal full header */}
+        <button
+          onClick={() => headerRef.current?.scrollIntoView({ behavior: 'smooth' })}
+          title="Show full header"
+          aria-label="Expand header"
+          style={{
+            display: 'inline-flex',
+            alignItems: 'center',
+            justifyContent: 'center',
+            width: 28,
+            height: 28,
+            borderRadius: 'var(--radius-sm)',
+            color: 'var(--text-muted)',
+            cursor: 'pointer',
+            transition: 'color var(--transition-fast)',
+            flexShrink: 0,
+          }}
+        >
+          <ChevronUp size={16} />
+        </button>
+      </div>
+
+      {/* Full channel header — observed for collapse trigger */}
+      <div
+        ref={headerRef}
+        style={{
+          padding: 'var(--space-5)',
+          backgroundColor: 'var(--bg-card)',
+          borderRadius: 'var(--radius-xl)',
+          border: '1px solid var(--border)',
+          marginBottom: 'var(--space-6)',
+        }}
+      >
+        {/* Identity row */}
+        <div style={{ display: 'flex', gap: 'var(--space-4)', alignItems: 'center', marginBottom: 'var(--space-5)' }}>
+          <img
+            src={
+              channel.imageUrl ||
+              `https://ui-avatars.com/api/?name=${encodeURIComponent(channel.name)}&background=242731&color=e1e2e6&size=80`
+            }
+            alt={`${channel.name} avatar`}
+            style={{
+              width: 64,
+              height: 64,
+              borderRadius: '50%',
+              objectFit: 'cover',
+              backgroundColor: 'var(--bg-hover)',
+              flexShrink: 0,
+            }}
+          />
+          <div style={{ minWidth: 0, flex: 1 }}>
+            <div style={{ display: 'flex', alignItems: 'center', gap: 'var(--space-2)', flexWrap: 'wrap' }}>
+              <h1 style={{ fontSize: 'var(--font-size-xl)', fontWeight: 600, color: 'var(--text-primary)', margin: 0 }}>
+                {channel.name}
+              </h1>
+              <PlatformBadge platform={channel.platform} />
+            </div>
+            <a
+              href={channel.url}
+              target="_blank"
+              rel="noopener noreferrer"
               style={{
-                fontSize: 'var(--font-size-2xl)',
-                fontWeight: 600,
-                color: 'var(--text-primary)',
-                margin: 0,
+                display: 'inline-flex',
+                alignItems: 'center',
+                gap: 'var(--space-1)',
+                color: 'var(--text-secondary)',
+                fontSize: 'var(--font-size-sm)',
+                marginTop: 2,
+                maxWidth: '100%',
+                overflow: 'hidden',
+                textOverflow: 'ellipsis',
+                whiteSpace: 'nowrap',
               }}
+              title={channel.url}
             >
-              {channel.name}
-            </h1>
-            <PlatformBadge platform={channel.platform} />
+              <span style={{ overflow: 'hidden', textOverflow: 'ellipsis', whiteSpace: 'nowrap' }}>{channel.url}</span>
+              <ExternalLink size={12} style={{ flexShrink: 0 }} />
+            </a>
+          </div>
+        </div>
+
+        {/* Control groups */}
+        <div
+          style={{
+            display: 'flex',
+            alignItems: 'flex-end',
+            gap: 'var(--space-5)',
+            flexWrap: 'wrap',
+            paddingTop: 'var(--space-4)',
+            borderTop: '1px solid var(--border)',
+          }}
+        >
+          {/* Monitoring group */}
+          <div style={{ display: 'flex', flexDirection: 'column', gap: 'var(--space-1)' }}>
+            <span style={{ fontSize: 'var(--font-size-xs)', color: 'var(--text-muted)', fontWeight: 500, textTransform: 'uppercase', letterSpacing: '0.04em' }}>
+              Monitoring
+            </span>
+            <div style={{ display: 'flex', alignItems: 'center', gap: 'var(--space-2)' }}>
+              <select
+                value={channel.monitoringMode}
+                onChange={handleMonitoringModeChange}
+                disabled={setMonitoringMode.isPending}
+                aria-label="Monitoring mode"
+                style={{ padding: 'var(--space-2) var(--space-3)', borderRadius: 'var(--radius-md)', fontSize: 'var(--font-size-sm)', minWidth: 130 }}
+              >
+                {MONITORING_MODE_OPTIONS.map((opt) => (
+                  <option key={opt.value} value={opt.value}>{opt.label}</option>
+                ))}
+              </select>
+              <div style={{ display: 'flex', alignItems: 'center', gap: 'var(--space-1)' }}>
+                <input
+                  type="number"
+                  min={1}
+                  value={localCheckInterval}
+                  onChange={(e) => setLocalCheckInterval(e.target.value === '' ? '' : Number(e.target.value))}
+                  aria-label="Check interval in minutes"
+                  title="Check interval (minutes)"
+                  style={{
+                    width: 56,
+                    padding: 'var(--space-2)',
+                    borderRadius: 'var(--radius-md)',
+                    border: '1px solid var(--border)',
+                    backgroundColor: 'var(--bg-main)',
+                    color: 'var(--text-primary)',
+                    fontSize: 'var(--font-size-sm)',
+                  }}
+                />
+                <span style={{ color: 'var(--text-muted)', fontSize: 'var(--font-size-xs)', whiteSpace: 'nowrap' }}>min</span>
+                <button
+                  onClick={handleCheckIntervalSave}
+                  disabled={
+                    localCheckInterval === '' ||
+                    Number(localCheckInterval) < 1 ||
+                    Number(localCheckInterval) === channel.checkInterval ||
+                    updateChannel.isPending
+                  }
+                  title={checkIntervalSaved ? 'Saved!' : 'Save check interval'}
+                  aria-label="Save check interval"
+                  style={{
+                    display: 'inline-flex',
+                    alignItems: 'center',
+                    justifyContent: 'center',
+                    width: 28,
+                    height: 28,
+                    borderRadius: 'var(--radius-sm)',
+                    color: checkIntervalSaved
+                      ? 'var(--success)'
+                      : localCheckInterval !== '' && Number(localCheckInterval) !== channel.checkInterval
+                        ? 'var(--accent)'
+                        : 'var(--text-muted)',
+                    cursor:
+                      localCheckInterval === '' ||
+                      Number(localCheckInterval) === channel.checkInterval ||
+                      updateChannel.isPending
+                        ? 'not-allowed'
+                        : 'pointer',
+                    opacity:
+                      localCheckInterval === '' ||
+                      Number(localCheckInterval) === channel.checkInterval
+                        ? 0.4
+                        : 1,
+                    transition: 'color var(--transition-fast), opacity var(--transition-fast)',
+                  }}
+                >
+                  {updateChannel.isPending ? (
+                    <Loader size={14} style={{ animation: 'spin 1s linear infinite' }} />
+                  ) : checkIntervalSaved ? (
+                    <CheckCircle size={14} />
+                  ) : (
+                    <Save size={14} />
+                  )}
+                </button>
+              </div>
+            </div>
           </div>
 
-          <a
-            href={channel.url}
-            target="_blank"
-            rel="noopener noreferrer"
-            style={{
-              display: 'inline-flex',
-              alignItems: 'center',
-              gap: 'var(--space-1)',
-              color: 'var(--text-secondary)',
-              fontSize: 'var(--font-size-sm)',
-              marginTop: 'var(--space-1)',
-              maxWidth: '100%',
-              overflow: 'hidden',
-              textOverflow: 'ellipsis',
-              whiteSpace: 'nowrap',
-            }}
-            title={channel.url}
-          >
-            <span style={{ overflow: 'hidden', textOverflow: 'ellipsis', whiteSpace: 'nowrap' }}>
-              {channel.url}
+          {/* Format group */}
+          <div style={{ display: 'flex', flexDirection: 'column', gap: 'var(--space-1)' }}>
+            <span style={{ fontSize: 'var(--font-size-xs)', color: 'var(--text-muted)', fontWeight: 500, textTransform: 'uppercase', letterSpacing: '0.04em' }}>
+              Format
             </span>
-            <ExternalLink size={12} style={{ flexShrink: 0 }} />
-          </a>
-
-          {/* Actions row */}
-          <div
-            style={{
-              display: 'flex',
-              alignItems: 'center',
-              gap: 'var(--space-3)',
-              marginTop: 'var(--space-4)',
-              flexWrap: 'wrap',
-            }}
-          >
-            {/* Monitoring mode dropdown */}
-            <select
-              value={channel.monitoringMode}
-              onChange={handleMonitoringModeChange}
-              disabled={setMonitoringMode.isPending}
-              aria-label="Monitoring mode"
-              style={{
-                padding: 'var(--space-2) var(--space-3)',
-                borderRadius: 'var(--radius-md)',
-                fontSize: 'var(--font-size-sm)',
-                minWidth: 140,
-              }}
-            >
-              {MONITORING_MODE_OPTIONS.map((opt) => (
-                <option key={opt.value} value={opt.value}>
-                  {opt.label}
-                </option>
-              ))}
-            </select>
-
-            {/* Format profile selector */}
             <select
               value={channel.formatProfileId ?? ''}
               onChange={handleFormatProfileChange}
               aria-label="Format profile"
-              style={{
-                padding: 'var(--space-2) var(--space-3)',
-                borderRadius: 'var(--radius-md)',
-                fontSize: 'var(--font-size-sm)',
-                minWidth: 140,
-              }}
+              style={{ padding: 'var(--space-2) var(--space-3)', borderRadius: 'var(--radius-md)', fontSize: 'var(--font-size-sm)', minWidth: 140 }}
             >
               <option value="">Default Profile</option>
               {formatProfiles?.map((fp) => (
-                <option key={fp.id} value={fp.id}>
-                  {fp.name}
-                </option>
+                <option key={fp.id} value={fp.id}>{fp.name}</option>
               ))}
             </select>
+          </div>
 
-            {/* Per-channel check interval */}
-            <div style={{ display: 'flex', alignItems: 'center', gap: 'var(--space-1)' }}>
-              <input
-                type="number"
-                min={1}
-                value={localCheckInterval}
-                onChange={(e) => setLocalCheckInterval(e.target.value === '' ? '' : Number(e.target.value))}
-                aria-label="Check interval in minutes"
-                title="Check interval (minutes)"
-                style={{
-                  width: 64,
-                  padding: 'var(--space-2) var(--space-2)',
-                  borderRadius: 'var(--radius-md)',
-                  border: '1px solid var(--border)',
-                  backgroundColor: 'var(--bg-main)',
-                  color: 'var(--text-primary)',
-                  fontSize: 'var(--font-size-sm)',
-                }}
-              />
-              <span style={{ color: 'var(--text-muted)', fontSize: 'var(--font-size-xs)', whiteSpace: 'nowrap' }}>min</span>
+          {/* Actions group */}
+          <div style={{ display: 'flex', flexDirection: 'column', gap: 'var(--space-1)' }}>
+            <span style={{ fontSize: 'var(--font-size-xs)', color: 'var(--text-muted)', fontWeight: 500, textTransform: 'uppercase', letterSpacing: '0.04em' }}>
+              Actions
+            </span>
+            <div style={{ display: 'flex', alignItems: 'center', gap: 'var(--space-2)' }}>
               <button
-                onClick={handleCheckIntervalSave}
-                disabled={
-                  localCheckInterval === '' ||
-                  Number(localCheckInterval) < 1 ||
-                  Number(localCheckInterval) === channel.checkInterval ||
-                  updateChannel.isPending
-                }
-                title={checkIntervalSaved ? 'Saved!' : 'Save check interval'}
-                aria-label="Save check interval"
-                style={{
-                  display: 'inline-flex',
-                  alignItems: 'center',
-                  justifyContent: 'center',
-                  width: 28,
-                  height: 28,
-                  borderRadius: 'var(--radius-sm)',
-                  color: checkIntervalSaved
-                    ? 'var(--success)'
-                    : localCheckInterval !== '' && Number(localCheckInterval) !== channel.checkInterval
-                      ? 'var(--accent)'
-                      : 'var(--text-muted)',
-                  cursor:
-                    localCheckInterval === '' ||
-                    Number(localCheckInterval) === channel.checkInterval ||
-                    updateChannel.isPending
-                      ? 'not-allowed'
-                      : 'pointer',
-                  opacity:
-                    localCheckInterval === '' ||
-                    Number(localCheckInterval) === channel.checkInterval
-                      ? 0.4
-                      : 1,
-                  transition: 'color var(--transition-fast), opacity var(--transition-fast)',
-                }}
-              >
-                {updateChannel.isPending ? (
-                  <Loader size={14} style={{ animation: 'spin 1s linear infinite' }} />
-                ) : checkIntervalSaved ? (
-                  <CheckCircle size={14} />
-                ) : (
-                  <Save size={14} />
-                )}
-              </button>
-            </div>
-
-            {/* Refresh & Scan button */}
-            <button
-              onClick={handleScan}
-              disabled={scanChannel.isPending || scanInProgress}
-              title={scanInProgress ? 'Scan in progress…' : 'Refresh & Scan'}
-              className="btn btn-ghost"
-              style={{ opacity: (scanChannel.isPending || scanInProgress) ? 0.6 : 1 }}
-            >
-              {(scanChannel.isPending || scanInProgress) ? (
-                <Loader size={14} style={{ animation: 'spin 1s linear infinite' }} />
-              ) : (
-                <RefreshCw size={14} />
-              )}
-              {scanInProgress ? 'Scanning…' : scanChannel.isPending ? 'Scanning…' : 'Refresh & Scan'}
-            </button>
-
-            {/* Collect Monitored button */}
-            <button
-              onClick={handleCollect}
-              disabled={collectMonitored.isPending}
-              title="Collect Monitored"
-              className="btn btn-ghost"
-              style={{ opacity: collectMonitored.isPending ? 0.6 : 1 }}
-            >
-              {collectMonitored.isPending ? (
-                <Loader size={14} style={{ animation: 'spin 1s linear infinite' }} />
-              ) : (
-                <Search size={14} />
-              )}
-              {collectMonitored.isPending ? 'Collecting...' : 'Collect Monitored'}
-            </button>
-
-            {/* Refresh Playlists button (YouTube only) */}
-            {isYouTube ? (
-              <button
-                onClick={handleRefreshPlaylists}
-                disabled={refreshPlaylists.isPending}
-                title="Refresh Playlists"
+                onClick={handleScan}
+                disabled={scanChannel.isPending || scanInProgress}
+                title={scanInProgress ? 'Scan in progress…' : 'Refresh & Scan'}
                 className="btn btn-ghost"
-                style={{ opacity: refreshPlaylists.isPending ? 0.6 : 1 }}
+                style={{ opacity: (scanChannel.isPending || scanInProgress) ? 0.6 : 1 }}
               >
-                {refreshPlaylists.isPending ? (
+                {(scanChannel.isPending || scanInProgress) ? (
                   <Loader size={14} style={{ animation: 'spin 1s linear infinite' }} />
                 ) : (
-                  <ListMusic size={14} />
+                  <RefreshCw size={14} />
                 )}
-                {refreshPlaylists.isPending ? 'Refreshing...' : 'Playlists'}
+                {scanInProgress ? 'Scanning…' : scanChannel.isPending ? 'Scanning…' : 'Scan'}
               </button>
-            ) : null}
+              <button
+                onClick={handleCollect}
+                disabled={collectMonitored.isPending}
+                title="Collect Monitored"
+                className="btn btn-ghost"
+                style={{ opacity: collectMonitored.isPending ? 0.6 : 1 }}
+              >
+                {collectMonitored.isPending ? (
+                  <Loader size={14} style={{ animation: 'spin 1s linear infinite' }} />
+                ) : (
+                  <Download size={14} />
+                )}
+                {collectMonitored.isPending ? 'Collecting…' : 'Collect'}
+              </button>
+              {isYouTube ? (
+                <button
+                  onClick={handleRefreshPlaylists}
+                  disabled={refreshPlaylists.isPending}
+                  title="Refresh Playlists"
+                  className="btn btn-ghost"
+                  style={{ opacity: refreshPlaylists.isPending ? 0.6 : 1 }}
+                >
+                  {refreshPlaylists.isPending ? (
+                    <Loader size={14} style={{ animation: 'spin 1s linear infinite' }} />
+                  ) : (
+                    <ListMusic size={14} />
+                  )}
+                  {refreshPlaylists.isPending ? 'Refreshing…' : 'Playlists'}
+                </button>
+              ) : null}
+            </div>
+          </div>
 
-            {/* Delete button */}
+          {/* Spacer + Delete */}
+          <div style={{ marginLeft: 'auto' }}>
             <button
               onClick={() => setShowDeleteConfirm(true)}
               className="btn btn-danger"
-              style={{ marginLeft: 'auto' }}
             >
               <Trash2 size={14} />
               Delete