feat(urd): mærket bliver ð, og frontend-bygget bliver deterministisk

## Mærket

Urds oplagte mærke var ᚢ uruz — bogstavet navnet begynder med i den ældre
futhark, præcis som Verdandes er ᚹ wunjo. Det blev tegnet sådan først.

Men uruz er allerede et af husets egne produkter, og dets egen
`scripts/gen-icons.ts` siger i sin kommentar at den "draws the Uruz rune (ᚢ)
in rune-gold" med "a tall left vertical, a shoulder across the top, and a
shorter" — altså samme glyf, samme konstruktion, kun en anden farve. To af
samme persons apps side om side på en hjemmeskærm, hvilket er nøjagtig det
sted mærket skal kunne skelnes.

ᚦ thurisaz blev forkastet et niveau nede af samme grund: en stav med en
trekant til højre, og det er ᚹ også. Ved 16px er de én form.

Så bogstavet frem for runen: ð, ethet i Urðr. Centreret ved at tælle malede
pixels frem for ud fra path-tallene, fordi en centreret kasse ikke er en
centreret glyf:

  verdande ᚹ   blæk x  53–108  midte 80.5  ·  y  18–131  midte 74.5
  urd      ð   blæk x  39–110  midte 74.5  ·  y  15–134  midte 74.5

Verdandes +5.5 i x er dens egen bevidste forskydning — en tung stav ved
siden af et let flag skal sidde til højre for midten for at se centreret ud.
ð er symmetrisk nok til at undvære den, og de to er enige i y.

Læsbarhed, målt: ð læses fra 32px og op. Ved 16px er det en klat, og det er
ᚹ også — en favicon er ikke det, der skiller to installerede apps i en dock.

`productRune` hedder nu `productMark`, fordi ð ikke er en rune.

## Determinisme

SvelteKits `kit.version.name` er som standard `Date.now()`. Millisekundet
landede i version.json, i index.html og i service-workeren, ændrede
indholdshashen på hver chunk der refererer dem, og dermed deres filnavne. To
bygninger af samme commit havde forskellige filer i sig.

Dockerfilen har i et år sagt at `-trimpath` og en tom buildid "keep the
output reproducible". Flagene gjorde deres arbejde; frontenden i binæren bar
et tidsstempel. Sætningen var falsk, og ingen læste den.

Fastgjort til VERSION, som udgivelsen allerede sender ind, og `dev` når
intet sætter den. Målt ved at bygge to gange og diffe træet, før og efter.
Prisen er at et lokalt `npm run build` ikke længere ligner en ny version for
service-workeren — hvilket kun betyder noget på en udrullet instans, hvor
udgivelsen sender det rigtige mærkat.

Det gør også CI's nye påstand mulig: de to images deler alle lag, så urd
bærer samme binær som verdande frem for en genbygning der tilfældigvis
matcher.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>

internal/httpapi/server.go

@@ -83,6 +83,9 @@ type Server struct {
 	shell    []byte
 	manifest []byte
 
+	// Icon paths this edition serves from another file. Empty in the full edition.
+	assets map[string]string
+
 	router chi.Router
 }
 
@@ -125,6 +128,11 @@ func New(cfg *config.Config, db *store.DB, log *slog.Logger, web fs.FS) *Server
 		} else {
 			s.shell, s.manifest = shell, manifest
 		}
+
+		s.assets = resolveNotesAssets(web, func(name, alias string) {
+			log.Error("this edition has no icon of its own at that path; it will serve verdande's",
+				"path", name, "wanted", alias)
+		})
 	}
 
 	if s.shell != nil {
@@ -789,6 +797,13 @@ func (s *Server) serveWeb(w http.ResponseWriter, r *http.Request) {
 		name = "index.html"
 	}
 
+	// This edition's own icon, where it has one. Before the Open rather than after,
+	// unlike the shell below: these are real files, so there is no fallback to get
+	// in the way, and resolveNotesAssets has already checked each one exists.
+	if alias, ok := s.assets[name]; ok {
+		name = alias
+	}
+
 	f, err := s.web.Open(name)
 	if errors.Is(err, fs.ErrNotExist) {
 		// A client-side route: hand back the shell and let the app route it.

internal/httpapi/shell.go

@@ -137,3 +137,41 @@ func contentTypeFor(name string) string {
 	}
 	return "text/html; charset=utf-8"
 }
+
+// notesAssetAliases maps the icon paths the shell and the manifest already point
+// at to urd's own files. Both sets are in the binary; the server decides.
+//
+// Aliased rather than renamed in the manifest, and the reason is the third entry.
+// Safari ignores a manifest's icons entirely and looks for `apple-touch-icon.png`
+// BY NAME — so pointing the manifest at urd-icon-192.png would have left iOS with
+// Verdande's mark, or, if that file were renamed too, with a screenshot of the page
+// as its home-screen icon. Keeping the paths and swapping the bytes behind them
+// fixes all four at once, including the favicon in `app.html`, which is not in the
+// manifest either.
+var notesAssetAliases = map[string]string{
+	"icon.svg":             "urd-icon.svg",
+	"icon-192.png":         "urd-icon-192.png",
+	"icon-512.png":         "urd-icon-512.png",
+	"apple-touch-icon.png": "urd-apple-touch-icon.png",
+}
+
+// resolveNotesAssets returns the aliases that have a file behind them, and reports
+// the ones that do not.
+//
+// Resolved once at startup rather than per request, so a missing file is one loud
+// line in the log instead of a silent fallback on every page load. The fallback is
+// still to Verdande's icon rather than to nothing: an icon is the one asset whose
+// absence turns into a broken-image placeholder on the Updates screen — which is
+// exactly how four releases of nolimit-views shipped with no icon — so serving the
+// wrong mark beats serving none.
+func resolveNotesAssets(web fs.FS, missing func(name, alias string)) map[string]string {
+	out := map[string]string{}
+	for name, alias := range notesAssetAliases {
+		if _, err := fs.Stat(web, alias); err != nil {
+			missing(name, alias)
+			continue
+		}
+		out[name] = alias
+	}
+	return out
+}

internal/httpapi/shell_test.go

@@ -233,3 +233,84 @@ func TestTheFullEditionServesTheBuiltFilesUnchanged(t *testing.T) {
 		})
 	}
 }
+
+// webWithIcons is builtWeb plus both editions' icons, as a real build has them.
+func webWithIcons() fstest.MapFS {
+	web := builtWeb()
+	for _, name := range []string{
+		"icon.svg", "icon-192.png", "icon-512.png", "apple-touch-icon.png",
+		"urd-icon.svg", "urd-icon-192.png", "urd-icon-512.png", "urd-apple-touch-icon.png",
+	} {
+		web[name] = &fstest.MapFile{Data: []byte("bytes of " + name)}
+	}
+	return web
+}
+
+// TestEachEditionServesItsOwnMark.
+//
+// Four paths, named one by one rather than counted: the favicon in app.html, the
+// manifest's two, and the one Safari looks for by name. The last is the reason
+// this is an alias rather than a rewritten manifest — Safari does not read the
+// manifest at all.
+func TestEachEditionServesItsOwnMark(t *testing.T) {
+	for _, tc := range []struct {
+		edition string
+		want    map[string]string
+	}{
+		{"notes", map[string]string{
+			"icon.svg":             "urd-icon.svg",
+			"icon-192.png":         "urd-icon-192.png",
+			"icon-512.png":         "urd-icon-512.png",
+			"apple-touch-icon.png": "urd-apple-touch-icon.png",
+		}},
+		// The control, and it is the half that stops this being a swap rather than
+		// a choice: the full edition must resolve nothing.
+		{"full", map[string]string{}},
+	} {
+		t.Run(tc.edition, func(t *testing.T) {
+			srv := serverWithWeb(t, tc.edition, webWithIcons())
+			if len(srv.assets) != len(tc.want) {
+				t.Errorf("%s edition aliases %d paths, want %d: %v", tc.edition, len(srv.assets), len(tc.want), srv.assets)
+			}
+			for path, alias := range tc.want {
+				if srv.assets[path] != alias {
+					t.Errorf("%s: %s resolves to %q, want %q", tc.edition, path, srv.assets[path], alias)
+				}
+			}
+			// And nothing else: an alias on a build asset would serve one file's
+			// bytes under another's hashed, immutable name.
+			for path := range srv.assets {
+				if _, ok := tc.want[path]; !ok {
+					t.Errorf("%s edition aliases %s, which is not an icon", tc.edition, path)
+				}
+			}
+			t.Logf("%s: %d aliased paths", tc.edition, len(srv.assets))
+		})
+	}
+}
+
+// TestAMissingMarkIsReportedAndFallsBack.
+//
+// The fallback is deliberate and it is the only place in this file that prefers
+// carrying on to failing: an icon's absence is a broken-image placeholder on the
+// one screen somebody reads before deciding whether to press update, so the wrong
+// mark beats no mark. What must not happen is it being quiet.
+func TestAMissingMarkIsReportedAndFallsBack(t *testing.T) {
+	web := webWithIcons()
+	delete(web, "urd-icon-512.png")
+
+	var reported []string
+	got := resolveNotesAssets(web, func(name, alias string) {
+		reported = append(reported, name+" → "+alias)
+	})
+
+	if len(reported) != 1 || reported[0] != "icon-512.png → urd-icon-512.png" {
+		t.Errorf("the missing icon was reported as %v, want exactly one naming both paths", reported)
+	}
+	if _, ok := got["icon-512.png"]; ok {
+		t.Error("a path with no file behind it was aliased anyway")
+	}
+	if got["icon.svg"] != "urd-icon.svg" {
+		t.Error("one missing icon took the other three with it")
+	}
+}