v3 M2: OpenAI Codex provider — real rate-limit % from local Codex rollouts

OpenAICodexProvider replaces the openai stub. It reads the rate-limit snapshot
the Codex CLI already records locally (no second auth): each turn Codex writes a
token_count event into $CODEX_HOME/sessions/**/rollout-*.jsonl whose
payload.rate_limits mirrors Claude's model — primary (5h) + secondary (weekly),
each with used_percent + resets_at + plan_type. The provider surfaces the
freshest such snapshot; a window whose reset time has passed is reported as a
fresh 0% (local read, so current in-session and self-heals between sessions).

primary -> s/sr, secondary -> w/wr, plan_type -> status ("Plus"/…),
rate_limit_reached_type -> "limited". No per-token cost (subscription), so the
two rate-limit bars are the metric, per the locked v3 decision.

Verified against the real ~/.codex: full daemon payload with openai active =
{pv:openai, pnm:"OpenAI Codex", ac:0x10a37f, st:"Plus", ok:true, weekly reset}.
registry test updated (openai now real, zai still stub); +7 provider tests.
113 passed, 2 Linux-only failures (baseline). spec: hiddenimport added.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

daemon/providers/__init__.py

@@ -9,11 +9,11 @@ from __future__ import annotations
 
 from .base import Provider, ProviderStatus, StubProvider
 from .anthropic import AnthropicProvider
+from .openai_codex import OpenAICodexProvider
 
 # Brand accents / labels for the not-yet-implemented providers, so the stub still
 # carries the right theme hint to the watch once firmware theming lands.
 _STUB_META = {
-    "openai": ("OpenAI Codex", "10a37f"),
     "zai": ("z.ai GLM", "3859ff"),
 }
 
@@ -21,8 +21,13 @@ _STUB_META = {
 def get_provider(pid: str) -> Provider:
     if pid == "anthropic":
         return AnthropicProvider()
+    if pid == "openai":
+        return OpenAICodexProvider()
     label, accent = _STUB_META.get(pid, (pid, "d97757"))
     return StubProvider(pid, label=label, accent=accent)
 
 
-__all__ = ["Provider", "ProviderStatus", "StubProvider", "AnthropicProvider", "get_provider"]
+__all__ = [
+    "Provider", "ProviderStatus", "StubProvider",
+    "AnthropicProvider", "OpenAICodexProvider", "get_provider",
+]