feat(core,web): add Fireworks Kimi K3; composer "+" menu, height and version-line fixes (#91)

Co-authored-by: Claude Opus 5 (1M context) <noreply@anthropic.com>

packages/core/test/model-catalog.test.ts

@@ -189,6 +189,7 @@ describe("model-catalog", () => {
       ["accounts/fireworks/models/deepseek-v4-flash", false],
       ["accounts/fireworks/models/deepseek-v4-pro", false],
       ["accounts/fireworks/models/glm-5p2", false],
+      ["accounts/fireworks/models/kimi-k3", true],
       ["accounts/fireworks/models/kimi-k2p7-code", true],
       ["accounts/fireworks/models/minimax-m3", true],
     ]);