perf(webui): delete dead config-manager-old.js + gzip + cache headers (Phase A)

Three WebUI cold-load wins:

1. DELETED containers/libreportal/frontend/js/components/config/config-manager-old.js
   66 KB / 68189 bytes. Zero references anywhere in source or deployed
   tree (confirmed via grep across containers/libreportal/). Pure dead
   code from a previous refactor — removed.

2. ADDED `compression` middleware (defensive require)
   Gzip-compresses JS/CSS/HTML/JSON responses. Typical ~70 % wire-size
   reduction → the 1.7 MB cold-load drops to ~500 KB. New package.json
   dependency; container's node_modules is baked into the image so the
   require is wrapped in try/catch to degrade silently until the image
   is next rebuilt (libreportal app install libreportal, or a full
   deploy). Once active: free wire-size win on every response.

3. ADDED static cache headers via staticOptions on express.static
   - JS/CSS/icons:     Cache-Control: max-age=3600 + ETag
                       (1h browser cache, cheap 304 revalidation after)
   - HTML files:       Cache-Control: no-cache + ETag
                       (always revalidates so SPA shell updates land
                       immediately after a deploy; 304 if unchanged)

   Repeat navigation in the same browser session skips ~25 script-tag
   round-trips entirely.

Net effect once compression deploys:
  - Cold load:    1.7 MB → ~500 KB on the wire (~70 % shrink)
  - Warm load:    25 conditional requests → 0 (served from cache for 1h)
  - Deploy lands: HTML revalidates immediately, JS/CSS picks up after 1h
                  or hard refresh

Phase B (defer non-critical scripts via SPA loadScript) and Phase C
(rebuild image / split the bind-mount story for node_modules) come
next; this commit is the safe Phase A foundation.

Signed-off-by: librelad <librelad@digitalangels.vip>

containers/libreportal/backend/package-lock.json

@@ -9,6 +9,7 @@
       "version": "1.0.0",
       "dependencies": {
         "bcryptjs": "^2.4.3",
+        "compression": "^1.8.1",
         "cookie-parser": "^1.4.6",
         "express": "^4.17.1",
         "jsonwebtoken": "^9.0.2",
@@ -130,6 +131,42 @@
         "url": "https://github.com/sponsors/ljharb"
       }
     },
+    "node_modules/compressible": {
+      "version": "2.0.18",
+      "resolved": "https://registry.npmjs.org/compressible/-/compressible-2.0.18.tgz",
+      "integrity": "sha512-AF3r7P5dWxL8MxyITRMlORQNaOA2IkAFaTr4k7BUumjPtRpGDTZpl0Pb1XCO6JeDCBdp126Cgs9sMxqSjgYyRg==",
+      "dependencies": {
+        "mime-db": ">= 1.43.0 < 2"
+      },
+      "engines": {
+        "node": ">= 0.6"
+      }
+    },
+    "node_modules/compression": {
+      "version": "1.8.1",
+      "resolved": "https://registry.npmjs.org/compression/-/compression-1.8.1.tgz",
+      "integrity": "sha512-9mAqGPHLakhCLeNyxPkK4xVo746zQ/czLH1Ky+vkitMnWfWZps8r0qXuwhwizagCRttsL4lfG4pIOvaWLpAP0w==",
+      "dependencies": {
+        "bytes": "3.1.2",
+        "compressible": "~2.0.18",
+        "debug": "2.6.9",
+        "negotiator": "~0.6.4",
+        "on-headers": "~1.1.0",
+        "safe-buffer": "5.2.1",
+        "vary": "~1.1.2"
+      },
+      "engines": {
+        "node": ">= 0.8.0"
+      }
+    },
+    "node_modules/compression/node_modules/negotiator": {
+      "version": "0.6.4",
+      "resolved": "https://registry.npmjs.org/negotiator/-/negotiator-0.6.4.tgz",
+      "integrity": "sha512-myRT3DiWPHqho5PrJaIRyaMv2kgYf0mUVgBNOYMuCH5Ki1yEiQaf/ZJuQ62nvpc44wL5WDbTX7yGJi1Neevw8w==",
+      "engines": {
+        "node": ">= 0.6"
+      }
+    },
     "node_modules/content-disposition": {
       "version": "0.5.4",
       "resolved": "https://registry.npmjs.org/content-disposition/-/content-disposition-0.5.4.tgz",
@@ -647,6 +684,14 @@
         "node": ">= 0.8"
       }
     },
+    "node_modules/on-headers": {
+      "version": "1.1.0",
+      "resolved": "https://registry.npmjs.org/on-headers/-/on-headers-1.1.0.tgz",
+      "integrity": "sha512-737ZY3yNnXy37FHkQxPzt4UZ2UWPWiCZWLvFZ4fu5cueciegX0zGPnrlY6bwRg4FdQOe9YU8MkmJwGhoMybl8A==",
+      "engines": {
+        "node": ">= 0.8"
+      }
+    },
     "node_modules/parseurl": {
       "version": "1.3.3",
       "resolved": "https://registry.npmjs.org/parseurl/-/parseurl-1.3.3.tgz",

containers/libreportal/backend/package.json

@@ -4,6 +4,7 @@
   "main": "server.js",
   "dependencies": {
     "bcryptjs": "^2.4.3",
+    "compression": "^1.8.1",
     "cookie-parser": "^1.4.6",
     "express": "^4.17.1",
     "jsonwebtoken": "^9.0.2",

containers/libreportal/backend/utils/middleware.js

@@ -4,6 +4,15 @@ const cookieParser = require('cookie-parser');
 const config = require('./config.js');
 const { verifyToken } = require('./auth.js');
 
+// compression is a new dependency (added to package.json). The Docker image
+// bakes node_modules at build time and routes/utils/server.js are bind-mounted
+// in compose.yml — but node_modules is NOT bind-mounted, so a "quick" deploy
+// (cp + restart) hits the old image without compression installed. We require
+// it defensively: present after the next image rebuild → ~70 % wire-size
+// reduction; absent → degrade silently to the previous uncompressed behaviour.
+let compression = null;
+try { compression = require('compression'); } catch (_) {}
+
 function requireAuth(req, res, next) {
   const token = req.cookies?.libreportal_token;
   if (!token) return res.status(401).json({ error: 'Unauthorized' });
@@ -20,7 +29,32 @@ function noStore(req, res, next) {
   next();
 }
 
+// Static-asset options:
+//   - 1h maxAge + ETag on JS/CSS/icons so repeated nav skips a network
+//     round-trip per file. ~25 script tags × ~5ms RTT each adds up otherwise.
+//   - HTML files get Cache-Control: no-cache (still uses ETag, so revalidation
+//     is cheap, but new deploys land immediately without waiting for cache
+//     expiry — the SPA shell is the file most likely to change between deploys).
+//   - dotfiles='ignore' so .auth.json is never served.
+const staticOptions = {
+  maxAge: '1h',
+  etag: true,
+  dotfiles: 'ignore',
+  setHeaders: (res, filePath) => {
+    if (filePath.endsWith('.html')) {
+      res.setHeader('Cache-Control', 'no-cache');
+    }
+  }
+};
+
 function setup(app) {
+  // Gzip-compress responses. JS/CSS/HTML/JSON typically shrink ~70 %, so the
+  // 1.7 MB of static assets the SPA loads on a cold cache drop to ~500 KB on
+  // the wire. compression defaults skip already-compressed types (images,
+  // gzipped tarballs) and small responses (<1 KB). Defensive — no-op if the
+  // module isn't installed (image not yet rebuilt with the new dep).
+  if (compression) app.use(compression());
+
   app.use(express.json());
   app.use(cookieParser());
 
@@ -31,12 +65,13 @@ function setup(app) {
   });
 
   // /data/* requires auth. express.static doesn't generate directory listings,
-  // so the only way to read anything is to know an exact path.
+  // so the only way to read anything is to know an exact path. noStore wins
+  // over staticOptions' maxAge for this prefix — auth-sensitive content
+  // should never be cached.
   app.use('/data', requireAuth, noStore, express.static(path.join(config.FRONTEND_PATH, 'data')));
 
   // All other static assets (js, css, icons, html partials, index.html) remain public.
-  // dotfiles='ignore' by default so .auth.json is never served.
-  app.use(express.static(config.FRONTEND_PATH));
+  app.use(express.static(config.FRONTEND_PATH, staticOptions));
 }
 
 module.exports = { setup, requireAuth };