refactor(generator): load themes & shared HTML from embedded template files (task s4)

Move the 12 theme HTML templates out of theme_*.go (~185KB of raw-string
literals) and the shared navDefs/faviconHeadHTML fragments out of
shared.go/favicon.go into separate .tmpl files under
internal/generator/templates/{themes,shared}/. A new templates subpackage
owns a //go:embed FS and exposes Theme(), Shared() and ThemeNames()
helpers so the binary still ships fully self-contained.

The hand-maintained themeRegistry map is replaced by on-startup
enumeration of the embedded FS; getTheme/ListThemes now derive theme
names from the template files themselves, and navDefs/faviconHeadHTML
are loaded once at package init. Rendered output is byte-equivalent — all
unit tests and integration tests pass, go vet is clean.

Made-with: Cursor

2 files changed, 402 insertions, 0 deletions

diff --git a/internal/generator/templates/shared/favicon_head.tmpl b/internal/generator/templates/shared/favicon_head.tmpl
new file mode 100644
index 0000000..e35bd5d
--- /dev/null
+++ b/internal/generator/templates/shared/favicon_head.tmpl
@@ -0,0 +1,2 @@
+
+    <link rel="icon" href="favicon.ico" sizes="any">
diff --git a/internal/generator/templates/shared/nav.tmpl b/internal/generator/templates/shared/nav.tmpl
new file mode 100644
index 0000000..0bbbf61
--- /dev/null
+++ b/internal/generator/templates/shared/nav.tmpl
@@ -0,0 +1,400 @@
+
+{{define "splashGate"}}
+<script>
+(function(){
+  try {
+    var sp = new URLSearchParams(location.search);
+    if (sp.get('splash') === '0') {
+      document.documentElement.classList.add('sno-splash-skip');
+      return;
+    }
+  } catch (_) {}
+  try {
+    if (/^#post-/.test(location.hash)) {
+      document.documentElement.classList.add('sno-splash-skip');
+      return;
+    }
+  } catch (_) {}
+  function isIndexLikePath(pathname) {
+    var p = pathname || '/';
+    if (p === '' || p === '/') return true;
+    var parts = p.split('/').filter(function(s) { return s.length; });
+    if (parts.length === 0) return true;
+    var last = parts[parts.length - 1].toLowerCase();
+    if (last === 'index.html' || last === 'index.htm') return true;
+    if (p.endsWith('/') && parts.length === 1) return true;
+    return false;
+  }
+  var onIndex = isIndexLikePath(location.pathname);
+  var ref = document.referrer;
+  function refIsSameSiteBlogPage(url) {
+    if (!url) return false;
+    try {
+      var ru = new URL(url), cu = new URL(location.href);
+      if (ru.origin !== cu.origin) return false;
+      if (isIndexLikePath(ru.pathname)) return true;
+      var rp = ru.pathname.split('/').filter(function(s) { return s.length; });
+      var rs = (rp.length ? rp[rp.length - 1] : '').toLowerCase();
+      return /^page\d+\.html$/.test(rs);
+    } catch (_) { return false; }
+  }
+  if (!onIndex || refIsSameSiteBlogPage(ref)) document.documentElement.classList.add('sno-splash-skip');
+})();
+</script>
+{{end}}
+
+{{define "navhints"}}
+<div class="nav-hints" role="region" aria-label="Keyboard shortcuts">
+    <span><kbd>j</kbd><kbd>k</kbd> or <kbd>↑</kbd><kbd>↓</kbd> select post</span>
+    <span><kbd>PgUp</kbd><kbd>PgDn</kbd> scroll</span>
+    <span><kbd>Enter</kbd> or click post to expand</span>
+    <span><kbd>Esc</kbd> close</span>
+    <span><kbd>h</kbd><kbd>l</kbd> or <kbd>←</kbd><kbd>→</kbd> change page</span>
+</div>
+{{end}}
+
+{{define "navSharedCSSInner"}}
+/* Thumbnail sizing in list view; modal overrides to full width. */
+.post-image { max-height:220px; max-width:100%; object-fit:cover; cursor:pointer; }
+#post-modal .post-image { max-height:none; width:100%; max-width:100%; object-fit:contain; cursor:default; }
+/* Semi-transparent modal backdrop so the WebGL scene stays visible behind
+   the expanded post. Theme-specific modal-inner keeps its own background. */
+.post-modal { background:rgba(0,0,0,0.55) !important; backdrop-filter:blur(6px) !important; }
+#post-modal.active { display:flex !important; align-items:center; justify-content:center; }
+#post-modal .modal-inner { width:fit-content; max-width:min(100%, 90vw); max-height:calc(100vh - 80px); overflow:auto; margin:0 auto !important; }
+/* Content area max-width across all themes */
+.overlay { max-width:1200px; margin-left:auto; margin-right:auto; }
+/* Pagination: newer + older in a footer bar (below scrollable posts, like the header) */
+.page-nav-dual { display:flex; justify-content:center; align-items:center; flex-wrap:wrap;
+                gap:clamp(16px,4vw,48px); }
+/* Flex column layout: let #post-content shrink so overflow-y scrolls; footer stays visible */
+#post-content.content { min-height:0; }
+.page-nav-footer { flex-shrink:0; width:100%; box-sizing:border-box; }
+.page-nav-footer .page-nav { margin:0; }
+/* ~Half-height footer bar vs default .page-nav padding */
+.page-nav-footer .page-nav a { padding-top:4px; padding-bottom:4px; }
+/* Host note under the site subtitle (all themes) */
+.logo-host { font-size:0.65rem; opacity:0.55; margin-top:4px; letter-spacing:0.3px; line-height:1.3; }
+/* Atom feed link in header (paired with transmit in .nav) */
+.nav { display:flex; align-items:center; gap:clamp(10px,2.2vw,20px); flex-wrap:wrap; justify-content:flex-end; }
+a.header-feed-link { font-size:0.8rem; text-decoration:none; opacity:0.82; letter-spacing:0.04em; white-space:nowrap; }
+a.header-feed-link:hover { opacity:1; text-decoration:underline; }
+/* Header logo/title can reopen the splash overlay. */
+.logo-mark, .logo-title h1, #sn-logo { cursor:pointer; }
+/* Full-viewport splash (theme-specific colours/animation on each .splash-THEMENAME) */
+#splash-overlay { position:fixed; inset:0; z-index:2000; display:flex; flex-direction:column; align-items:center;
+  justify-content:center; text-align:center; padding:max(16px,4vw); box-sizing:border-box; cursor:pointer;
+  transition:opacity .55s ease, visibility .55s ease, transform .55s ease; }
+#splash-overlay.splash--dismissed { opacity:0 !important; visibility:hidden !important;
+  pointer-events:none !important; transform:scale(1.02); }
+#splash-overlay:focus { outline:2px solid rgba(255,255,255,0.35); outline-offset:4px; }
+/* Vignette over WebGL so 3D motion does not overpower the edges */
+#splash-overlay::before { content:""; position:absolute; inset:0; z-index:1; pointer-events:none;
+  background: radial-gradient(ellipse 92% 82% at 50% 42%, rgba(0,0,0,0) 32%, rgba(0,0,0,0.26) 68%, rgba(0,0,0,0.48) 100%); }
+.splash-title { font-weight:700; letter-spacing:0.06em; line-height:1.15; }
+.splash-tag { margin-top:0.35rem; font-size:0.76rem; letter-spacing:0.2em; text-transform:uppercase; }
+.splash-hint { margin-top:1.25rem; font-size:0.72rem; letter-spacing:0.12em; }
+#splash-overlay .splash-gl-canvas { position:absolute; inset:0; width:100%; height:100%; display:block; z-index:0; pointer-events:none; }
+/* Frosted panel so title/tag/hint stay readable over busy shaders */
+#splash-overlay .splash-inner { position:relative; z-index:2; max-width:min(520px,92vw);
+  padding: clamp(1.15rem, 3.2vw, 1.75rem) clamp(1.3rem, 3.8vw, 1.95rem); border-radius:14px;
+  background: rgba(0, 0, 0, 0.58); backdrop-filter: blur(14px); -webkit-backdrop-filter: blur(14px);
+  box-shadow: 0 14px 44px rgba(0, 0, 0, 0.58), inset 0 1px 0 rgba(255, 255, 255, 0.07); }
+#splash-overlay.splash-brutalist .splash-inner.splash-frame {
+  padding: clamp(1.4rem, 4.5vw, 2.25rem) clamp(1.1rem, 3.5vw, 1.9rem); background: rgba(0, 0, 0, 0.78); }
+html.sno-splash-skip #splash-overlay { display:none !important; visibility:hidden !important; pointer-events:none !important; }
+/* Images embedded in markdown posts */
+.post-text img { max-width:100%; max-height:320px; object-fit:contain; border-radius:6px; cursor:pointer; }
+#post-modal .post-text img, #modal-content img { max-height:none; cursor:default; }
+/* Markdown post typography: restore spacing stripped by the global reset */
+.post-text p { margin:0.65em 0; }
+.post-text ul, .post-text ol { margin:0.65em 0; padding-left:1.8em; }
+.post-text li { margin:0.3em 0; }
+.post-text p:first-child { margin-top:0; }
+.post-text p:last-child, .post-text ul:last-child, .post-text ol:last-child { margin-bottom:0; }
+{{end}}
+
+{{define "navmodal"}}
+<div class="post-modal" id="post-modal" role="dialog" aria-modal="true" aria-label="Expanded post">
+    <div class="modal-inner">
+        <button class="modal-close" onclick="closeModal()">[ ESC ] CLOSE</button>
+        <div id="modal-content"></div>
+    </div>
+</div>
+{{end}}
+
+{{define "navscript"}}
+<script>
+    const SNONUX_SOUNDS = {{.ThemeSoundsJSON}};
+    function snonuxWaveType(w) {
+        if (w === 'square') return 'square';
+        if (w === 'triangle') return 'triangle';
+        return 'sine';
+    }
+    (function splashSetup() {
+        var el = document.getElementById('splash-overlay');
+        if (!el) return;
+        var splashAudioCtx = null;
+        var splashChimePlayed = false;
+        function playSplashChime() {
+            if (splashChimePlayed) return;
+            try {
+                if (!splashAudioCtx) {
+                    splashAudioCtx = new (window.AudioContext || window.webkitAudioContext)();
+                }
+                var ctx = splashAudioCtx;
+                function ring() {
+                    splashChimePlayed = true;
+                    var now = ctx.currentTime;
+                    var sp = SNONUX_SOUNDS.splash;
+                    var freqs = sp.freqs;
+                    var spacing = sp.spacing != null ? sp.spacing : 0.075;
+                    var gainAm = sp.gain != null ? sp.gain : 0.1;
+                    var wave = snonuxWaveType(sp.wave);
+                    var i, osc, g, t0;
+                    for (i = 0; i < freqs.length; i++) {
+                        osc = ctx.createOscillator();
+                        g = ctx.createGain();
+                        osc.connect(g);
+                        g.connect(ctx.destination);
+                        osc.type = wave;
+                        osc.frequency.value = freqs[i];
+                        t0 = now + i * spacing;
+                        g.gain.setValueAtTime(0, t0);
+                        g.gain.linearRampToValueAtTime(gainAm, t0 + 0.028);
+                        g.gain.exponentialRampToValueAtTime(0.001, t0 + 0.52);
+                        osc.start(t0);
+                        osc.stop(t0 + 0.55);
+                    }
+                }
+                ctx.resume().then(ring).catch(function() {});
+            } catch (_) {}
+        }
+        function dismiss() {
+            if (el.classList.contains('splash--dismissed')) return;
+            el.classList.add('splash--dismissed');
+            el.setAttribute('aria-hidden', 'true');
+        }
+        function show() {
+            document.documentElement.classList.remove('sno-splash-skip');
+            el.classList.remove('splash--dismissed');
+            el.removeAttribute('aria-hidden');
+            el.focus({ preventScroll: true });
+        }
+        function openSplashFromHeader(e) {
+            if (e.target.closest('a')) return;
+            e.preventDefault();
+            var modal = document.getElementById('post-modal');
+            if (modal) modal.classList.remove('active');
+            show();
+        }
+        var triggers = document.querySelectorAll('.logo-mark, .logo-title h1, #sn-logo');
+        triggers.forEach(function(trigger) {
+            trigger.addEventListener('click', openSplashFromHeader);
+        });
+        window._snonuxDismissSplash = dismiss;
+        window._snonuxShowSplash = show;
+        if (document.documentElement.classList.contains('sno-splash-skip')) {
+            dismiss();
+            return;
+        }
+        playSplashChime();
+        el.addEventListener('pointerdown', function() { playSplashChime(); }, { passive: true });
+        el.addEventListener('click', function(e) { e.preventDefault(); dismiss(); });
+        el.focus({ preventScroll: true });
+    })();
+
+    // === KEYBOARD NAVIGATION ===
+    // j / ArrowDown  → next post       k / ArrowUp    → previous post
+    // h / ArrowLeft  → previous page   l / ArrowRight → next page
+    // PageUp/PageDown → scroll the post list; re-highlight post at top of visible area
+    // Enter / click post → expand modal    Esc → close modal
+    const posts = document.querySelectorAll('.post');
+    let currentIndex = posts.length > 0 ? 0 : -1;
+    const prevPageURL = {{.PrevPageJSON}};
+    const nextPageURL = {{.NextPageJSON}};
+
+    if (currentIndex >= 0) selectPost(0);
+
+    function setActiveHighlight(index, playSound, scrollIntoView) {
+        if (posts.length === 0) return;
+        if (currentIndex >= 0) posts[currentIndex].classList.remove('post-active');
+        currentIndex = Math.max(0, Math.min(index, posts.length - 1));
+        posts[currentIndex].classList.add('post-active');
+        if (scrollIntoView) {
+            posts[currentIndex].scrollIntoView({ behavior: 'smooth', block: 'nearest' });
+        }
+        if (playSound) playNavSound();
+    }
+
+    function selectPost(index) {
+        setActiveHighlight(index, true, true);
+    }
+
+    /** Pick the post that should be active for the current viewport (anchor near top of visible area). */
+    function activeIndexForVisibleRegion(sc) {
+        if (posts.length === 0) return -1;
+        var scrTop, scrBot, anchorY;
+        if (sc) {
+            var scr = sc.getBoundingClientRect();
+            scrTop = scr.top;
+            scrBot = scr.bottom;
+            anchorY = scr.top + Math.min(scr.height * 0.18, 100);
+        } else {
+            scrTop = 0;
+            scrBot = window.innerHeight;
+            anchorY = window.innerHeight * 0.15;
+        }
+        var i, pr;
+        for (i = 0; i < posts.length; i++) {
+            pr = posts[i].getBoundingClientRect();
+            if (pr.top <= anchorY && anchorY < pr.bottom) return i;
+        }
+        for (i = 0; i < posts.length; i++) {
+            pr = posts[i].getBoundingClientRect();
+            if (pr.bottom > scrTop && pr.top < scrBot) return i;
+        }
+        return posts.length - 1;
+    }
+
+    function playNavSound() {
+        try {
+            var n = SNONUX_SOUNDS.nav;
+            const ctx = new (window.AudioContext || window.webkitAudioContext)();
+            const osc = ctx.createOscillator();
+            const gain = ctx.createGain();
+            osc.connect(gain); gain.connect(ctx.destination);
+            osc.frequency.value = n.freq;
+            osc.type = snonuxWaveType(n.wave);
+            var dur = n.dur != null ? n.dur : 0.08;
+            var g = n.gain != null ? n.gain : 0.12;
+            gain.gain.setValueAtTime(g, ctx.currentTime);
+            gain.gain.exponentialRampToValueAtTime(0.001, ctx.currentTime + dur);
+            osc.start(ctx.currentTime); osc.stop(ctx.currentTime + dur + 0.02);
+        } catch (_) {}
+    }
+
+    function playOpenSound() {
+        try {
+            var o = SNONUX_SOUNDS.open;
+            const ctx = new (window.AudioContext || window.webkitAudioContext)();
+            const osc = ctx.createOscillator();
+            const gain = ctx.createGain();
+            osc.connect(gain); gain.connect(ctx.destination);
+            osc.type = snonuxWaveType(o.wave);
+            var dur = o.dur != null ? o.dur : 0.14;
+            var g = o.gain != null ? o.gain : 0.1;
+            osc.frequency.setValueAtTime(o.start, ctx.currentTime);
+            osc.frequency.exponentialRampToValueAtTime(o.end, ctx.currentTime + dur);
+            gain.gain.setValueAtTime(g, ctx.currentTime);
+            gain.gain.exponentialRampToValueAtTime(0.001, ctx.currentTime + dur + 0.06);
+            osc.start(ctx.currentTime); osc.stop(ctx.currentTime + dur + 0.07);
+        } catch (_) {}
+    }
+
+    function playCloseSound() {
+        try {
+            var c = SNONUX_SOUNDS.close;
+            const ctx = new (window.AudioContext || window.webkitAudioContext)();
+            const osc = ctx.createOscillator();
+            const gain = ctx.createGain();
+            osc.connect(gain); gain.connect(ctx.destination);
+            osc.type = snonuxWaveType(c.wave);
+            var dur = c.dur != null ? c.dur : 0.15;
+            var g = c.gain != null ? c.gain : 0.1;
+            osc.frequency.setValueAtTime(c.start, ctx.currentTime);
+            osc.frequency.exponentialRampToValueAtTime(c.end, ctx.currentTime + dur);
+            gain.gain.setValueAtTime(g, ctx.currentTime);
+            gain.gain.exponentialRampToValueAtTime(0.001, ctx.currentTime + dur + 0.05);
+            osc.start(ctx.currentTime); osc.stop(ctx.currentTime + dur + 0.06);
+        } catch (_) {}
+    }
+
+    function openPostAt(index, scrollIntoView) {
+        if (posts.length === 0) return;
+        setActiveHighlight(index, false, !!scrollIntoView);
+        var post = posts[currentIndex];
+        var postText = post ? post.querySelector('.post-text') : null;
+        if (!postText) return;
+        var modal = document.getElementById('post-modal');
+        var modalInner = modal ? modal.querySelector('.modal-inner') : null;
+        document.getElementById('modal-content').innerHTML = postText.innerHTML;
+        modal.classList.add('active');
+        modal.scrollTop = 0;
+        if (modalInner) {
+            modalInner.scrollTop = 0;
+            requestAnimationFrame(function() {
+                modalInner.scrollIntoView({ block: 'center', inline: 'nearest' });
+            });
+        }
+        playOpenSound();
+    }
+
+    function closeModal() {
+        document.getElementById('post-modal').classList.remove('active');
+        playCloseSound();
+    }
+
+    (function postClickOpen() {
+        posts.forEach(function(post, idx) {
+            post.addEventListener('click', function(e) {
+            if (e.target.closest('a, button, audio, video, input, textarea, select, label')) return;
+                openPostAt(idx, true);
+            });
+        });
+    })();
+
+    (function deepLinkFromHash() {
+        var h = location.hash;
+        if (!h || h.indexOf('#post-') !== 0) return;
+        var id = decodeURIComponent(h.slice(6));
+        var el = document.getElementById('post-' + id);
+        if (!el) return;
+        var idx = parseInt(el.getAttribute('data-index'), 10);
+        if (isNaN(idx)) return;
+        openPostAt(idx, true);
+    })();
+
+    document.addEventListener('keydown', function(e) {
+        if (e.target.tagName === 'INPUT' || e.target.tagName === 'TEXTAREA') return;
+        var splash = document.getElementById('splash-overlay');
+        if (splash && !splash.classList.contains('splash--dismissed')) {
+            if (e.key === 'Enter' || e.key === ' ' || e.key === 'Escape') {
+                e.preventDefault();
+                if (window._snonuxDismissSplash) window._snonuxDismissSplash();
+            }
+            return;
+        }
+        if (document.getElementById('post-modal').classList.contains('active')) {
+            if (e.key === 'Escape') { closeModal(); e.preventDefault(); }
+            return;
+        }
+        switch (e.key) {
+            case 'PageUp':
+            case 'PageDown': {
+                var sc = document.getElementById('post-content');
+                var step = (sc && sc.clientHeight) ? sc.clientHeight : window.innerHeight;
+                var dy = (e.key === 'PageUp') ? -step : step;
+                if (sc) {
+                    sc.scrollTop += dy;
+                } else {
+                    window.scrollBy(0, dy);
+                }
+                var idx = activeIndexForVisibleRegion(sc);
+                if (idx >= 0) setActiveHighlight(idx, true, false);
+                e.preventDefault();
+                break;
+            }
+            case 'j': case 'ArrowDown':  selectPost(currentIndex + 1); e.preventDefault(); break;
+            case 'k': case 'ArrowUp':    selectPost(currentIndex - 1); e.preventDefault(); break;
+            case 'h': case 'ArrowLeft':
+                if (prevPageURL) { playNavSound(); window.location.href = prevPageURL; }
+                e.preventDefault(); break;
+            case 'l': case 'ArrowRight':
+                if (nextPageURL) { playNavSound(); window.location.href = nextPageURL; }
+                e.preventDefault(); break;
+            case 'Enter': openPostAt(currentIndex, true); e.preventDefault(); break;
+        }
+    });
+</script>
+{{end}}