feat: model-aware multi-plan account routing (#57)

fix: update model catalog — gpt-5.4/5.3-codex removed, gpt-5.2-codex is new flagship

fix: preserve model name suffixes (-fast, -high, etc.) in API responses

feat: model name suffix system + service_tier + Docker persistence fix (#35)

feat: add proxy pool for per-account proxy routing

feat: add gpt-5.4 + codex-spark support, matrix model selector, extended reasoning efforts

fix: auto-admit new Codex models from backend API

refactor: extract startServer() + path abstraction for Electron reuse

chore: deduplicate model selector, auto-extract chromium version, harden update pipeline

fix: filter non-Codex models from backend to prevent resolveModelId fallback breakage

feat: dynamic model list fetching from Codex backend (#9)