feat(web): B4 枚举标签映射 — labelFor 未知值原样显示

- 新增 lib/enums.ts：platform/mood 标签 + labelFor(kind,value)，未知值原样返回（display-raw 红线），注释标明权威来源是 GET /api/v1/meta/enums
- 4 处 mood 渲染改用标签（Nav/TopBar/chat×2）；未动 types.ts 的 MODES/Mode
- 新增纯逻辑测试 enums.test.ts（47 项，esbuild+node，零新依赖）
- 未动 admin channelFields 的第二份 PLATFORM_LABEL（记入待办）

frontend/web/src/lib/enums.test.ts

@@ -0,0 +1,89 @@
+// Logic test for the Web-side enum mirror (Android collaboration B4, design/07
+// §6): the platform/mood id → label mapping and, above all, the unknown-value
+// fallback red line — an unlisted value must come back raw, never dropped and
+// never a throw. The project has no frontend test runner, so this is a
+// dependency-free plain-node check that drives the real `labelFor` and throws on
+// the first failure.
+//
+// Run it with the esbuild that already ships with vite (no new dependency, no
+// package.json change):
+//
+//   cd frontend/web \
+//     && ./node_modules/.bin/esbuild src/lib/enums.test.ts \
+//          --bundle --platform=node --format=esm \
+//          --outfile=/tmp/cyrene-enums.test.mjs \
+//     && node /tmp/cyrene-enums.test.mjs
+//
+// `tsc --noEmit` (part of `npm run build`) type-checks this file, which is why it
+// imports nothing from node:*.
+
+import { labelFor, MOOD_LABELS, PLATFORM_LABELS } from "./enums";
+
+let checks = 0;
+
+function ok(cond: boolean, what: string): void {
+  checks += 1;
+  if (!cond) throw new Error(`FAILED: ${what}`);
+}
+
+function eq(got: string, want: string, what: string): void {
+  ok(got === want, `${what} — got ${JSON.stringify(got)}, want ${JSON.stringify(want)}`);
+}
+
+// Every known platform id resolves to its default Chinese label.
+const platformCases: Array<[string, string]> = [
+  ["web", "网页"],
+  ["kook", "KOOK"],
+  ["qq-obv11", "QQ"],
+  ["weixin-ilink", "微信"],
+  ["telegram", "Telegram"],
+  ["webhook", "Webhook"],
+];
+for (const [id, label] of platformCases) {
+  eq(labelFor("platform", id), label, `platform ${id} → ${label}`);
+}
+
+// Every known mood id resolves to its default Chinese label.
+const moodCases: Array<[string, string]> = [
+  ["calm", "平静"],
+  ["happy", "开心"],
+  ["excited", "兴奋"],
+  ["sad", "低落"],
+  ["angry", "生气"],
+];
+for (const [id, label] of moodCases) {
+  eq(labelFor("mood", id), label, `mood ${id} → ${label}`);
+}
+
+// The mirrored tables are complete and non-empty (a label is always available).
+eq(String(Object.keys(PLATFORM_LABELS).length), "6", "platform table size");
+eq(String(Object.keys(MOOD_LABELS).length), "5", "mood table size");
+for (const kind of ["platform", "mood"] as const) {
+  const source = kind === "platform" ? PLATFORM_LABELS : MOOD_LABELS;
+  for (const [id, label] of Object.entries(source)) {
+    eq(labelFor(kind, id), label, `${kind} table entry ${id}`);
+    ok(label !== "", `${kind} ${id} has a non-empty label`);
+  }
+}
+
+// RED LINE (display-raw): an unknown value comes back exactly as received.
+eq(labelFor("mood", "sleepy"), "sleepy", "unknown mood returns raw");
+eq(labelFor("platform", "discord"), "discord", "unknown platform returns raw");
+eq(labelFor("mood", "此刻心情很好"), "此刻心情很好", "unknown non-ASCII mood returns raw");
+eq(labelFor("platform", "web:v2"), "web:v2", "unknown id-shaped value returns raw");
+eq(labelFor("mood", "<script>alert(1)</script>"), "<script>alert(1)</script>", "unknown markup returns raw");
+
+// Case variants are not contract ids, so they fall through to display-raw
+// without throwing.
+eq(labelFor("mood", "CALM"), "CALM", "uppercase mood returns raw");
+eq(labelFor("platform", "Telegram"), "Telegram", "mixed-case platform returns raw");
+
+// Blank / absent / whitespace values must not crash. Whitespace is preserved
+// verbatim (no trimming — the function only maps, never rewrites).
+eq(labelFor("mood", ""), "", "empty mood");
+eq(labelFor("platform", ""), "", "empty platform");
+eq(labelFor("mood", undefined), "", "undefined mood");
+eq(labelFor("mood", null), "", "null mood");
+eq(labelFor("mood", " calm "), " calm ", "padded mood returns raw");
+
+console.log(`enums.test.ts OK — ${checks} checks`);

frontend/web/src/lib/enums.ts

@@ -0,0 +1,55 @@
+/**
+ * Web-side mirror of the shared client enumerations (Android collaboration B4,
+ * design/07 §6).
+ *
+ * The authority is the backend: `GET /api/v1/meta/enums` publishes
+ * `{platforms, moods, modes, unknown}` as `{id,label}` pairs. This module mirrors
+ * the platform and mood tables (the mode union already lives in `types.ts` as
+ * `MODES`/`Mode` and is deliberately not duplicated here); a client with i18n may
+ * override any label.
+ *
+ * RED LINE — unknown-value fallback (the published `unknown: "display-raw"`): a
+ * value that is not in the table is returned AS RECEIVED and displayed raw.
+ * Never drop it, never throw, never substitute a placeholder. The backend adding a
+ * value is a non-breaking contract change, so a client that lags must degrade
+ * gracefully instead of losing the badge/label.
+ */
+
+/** The enum tables the Web client renders labels for. */
+export type EnumKind = "platform" | "mood";
+
+/** Platform id → default Chinese label. Mirrors the `platforms` table. */
+export const PLATFORM_LABELS: Readonly<Record<string, string>> = {
+  web: "网页",
+  kook: "KOOK",
+  "qq-obv11": "QQ",
+  "weixin-ilink": "微信",
+  telegram: "Telegram",
+  webhook: "Webhook",
+};
+
+/** Mood id → default Chinese label. Mirrors the `moods` table. */
+export const MOOD_LABELS: Readonly<Record<string, string>> = {
+  calm: "平静",
+  happy: "开心",
+  excited: "兴奋",
+  sad: "低落",
+  angry: "生气",
+};
+
+/** The id → label table of one enum kind. */
+function table(kind: EnumKind): Readonly<Record<string, string>> {
+  return kind === "platform" ? PLATFORM_LABELS : MOOD_LABELS;
+}
+
+/**
+ * Resolve `value` to its default display label. A known id yields the table's
+ * label; anything else — an unknown id, an empty/blank string, a value whose
+ * case differs from the lowercase contract id — yields `value` unchanged
+ * (display-raw), and an absent value yields `""`. This never throws and never
+ * drops a value: see the unknown-value red line above.
+ */
+export function labelFor(kind: EnumKind, value: string | null | undefined): string {
+  if (!value) return "";
+  return table(kind)[value] ?? value;
+}