feat(i18n): add multi-language support for buddy reactions, achievements, and MCP responses

.gitignore

@@ -38,3 +38,6 @@ coverage/
 main.py
 pyproject.toml
 uv.lock
+
+# i18n
+i18n.lock

CONTRIBUTING.md

@@ -60,6 +60,16 @@ Species art lives in `server/art.ts` and `statusline/buddy-status.sh`. Each spec
 ### New Reactions
 Reaction templates are in `server/reactions.ts`. Species-specific reactions go in `SPECIES_REACTIONS`, general ones in `REACTIONS`.
 
+### Translations
+Locale files live in `locales/<code>.json` (e.g. `locales/en.json`, `locales/es.json`). To add a new language:
+
+1. Copy `locales/en.json` to `locales/<code>.json`
+2. Set `"_language"` to the language name (e.g. `"Español"`)
+3. Translate the string values (keep `{variable}` placeholders and `*asterisk actions*` intact)
+4. Run `bun test` to validate the locale structure
+
+The i18n module (`server/i18n.ts`) auto-discovers locale files by scanning `locales/*.json`. No code changes needed — just drop in the file.
+
 ## DCO (Developer Certificate of Origin)
 
 Every commit to this repo must be **signed off** with the Developer

cli/index.ts

@@ -114,6 +114,7 @@ In Claude Code:
   /buddy position   Show or set bubble position (tmux only)
   /buddy rarity     Show or hide rarity stars (tmux only)
   /buddy width      Set bubble text width in chars (10-60, tmux only)
+  /buddy language   Show or set buddy language (e.g. 'en', 'es', 'ja')
 
 Usage:
   bun run <command>           e.g. bun run show, bun run doctor

cli/settings.ts

@@ -8,6 +8,7 @@
  */
 
 import { loadConfig, saveConfig } from "../server/state.ts";
+import { AVAILABLE_LOCALES } from "../server/i18n.ts";
 
 const args = process.argv.slice(2);
 const key = args[0];
@@ -20,9 +21,11 @@ if (!key) {
   ─────────────────────
   Comment cooldown:  ${cfg.commentCooldown}s    (0 = no throttling, default 30)
   Reaction TTL:      ${cfg.reactionTTL}s    (0 = permanent, default 0)
+  Language:          ${cfg.language}    (${AVAILABLE_LOCALES[cfg.language] ?? cfg.language})
 
   Change:  bun run settings cooldown <seconds>
            bun run settings ttl <seconds>
+           bun run settings language <code>
 `);
   process.exit(0);
 }
@@ -63,6 +66,25 @@ if (key === "ttl") {
   process.exit(0);
 }
 
+if (key === "language") {
+  if (value === undefined) {
+    const cfg = loadConfig();
+    console.log(`Language: ${cfg.language} (${AVAILABLE_LOCALES[cfg.language] ?? cfg.language})`);
+    console.log("Available:", Object.entries(AVAILABLE_LOCALES).map(([c, n]) => `${c} (${n})`).join(", "));
+    process.exit(0);
+  }
+
+  if (!AVAILABLE_LOCALES[value]) {
+    console.error(`Error: unknown language "${value}"`);
+    console.error("Available:", Object.keys(AVAILABLE_LOCALES).join(", "));
+    process.exit(1);
+  }
+
+  const cfg = saveConfig({ language: value });
+  console.log(`Updated: language → ${cfg.language} (${AVAILABLE_LOCALES[cfg.language]})`);
+  process.exit(0);
+}
+
 console.error(`Unknown setting: ${key}`);
-console.error("Available: cooldown, ttl");
+console.error("Available: cooldown, ttl, language");
 process.exit(1);

i18n.json

@@ -0,0 +1,18 @@
+{
+  "$schema": "https://lingo.dev/schema/i18n.json",
+  "version": "1.10",
+  "locale": {
+    "source": "en",
+    "targets": ["zh", "es", "ja", "de", "fr", "pt", "ko", "ru", "ro", "uk", "tr", "hi", "it", "pl", "vi", "ar", "th"]
+  },
+  "buckets": {
+    "json": {
+      "include": ["locales/[locale].json"]
+    }
+  },
+  "provider": {
+    "id": "openrouter",
+    "model": "anthropic/claude-opus-4.6",
+    "prompt": "You are translating a JSON locale file for claude-buddy — a tamagotchi-style coding companion that lives in a developer's terminal. Preserve: (1) roleplay asterisk actions like *purrs*, *knocks error off table* (translate the action verb, keep the asterisks), (2) the playful, snarky, affectionate tone, (3) all {variable} placeholders EXACTLY as-is, (4) all emoji, (5) JSON structure (keys, nesting, array lengths) EXACTLY as-is. Translate from {SOURCE_LOCALE} to {TARGET_LOCALE}. Sound natural to a native developer — use casual/colloquial register, not formal textbook language."
+  }
+}