build: token-monitor v0.1.0 — modular LLM API quota visibility

Implements modular provider probing with two distinct header schemas:
- Teams direct (unified schema): 5h/7d utilization floats, status, reset countdown
- Shelley proxy (classic schema): token/request counts + Exedev-Gateway-Cost (USD/call)
- api-ateam: reports no billing data (confirmed non-existent by recon)

Key: uses claude-haiku-4-5-20251001 for minimal probe calls (1 token).
Rate-limit headers present on ALL responses (200 and 429).

113/113 tests passing.

Built from Face recon (trentuna/a-team#91) — live header capture confirmed
unified schema with utilization floats replaces old per-count schema.

providers/index.js

@@ -0,0 +1,47 @@
+/**
+ * providers/index.js — provider registry
+ *
+ * Reads ~/.pi/agent/models.json and returns typed provider config for all
+ * providers we know how to probe. Non-anthropic-messages providers (e.g. zai)
+ * are silently skipped.
+ */
+
+import { readFileSync } from 'fs';
+import { homedir } from 'os';
+
+/**
+ * Classify a provider by name and config.
+ * @returns {'teams-direct'|'shelley-proxy'|'api-direct'|null}
+ */
+function classifyProvider(name, config) {
+  if (name === 'shelley-proxy') return 'shelley-proxy';
+  if (name === 'api-ateam') return 'api-direct';
+  if (config.api === 'anthropic-messages' && name.startsWith('team-')) return 'teams-direct';
+  return null; // skip (zai, etc.)
+}
+
+/**
+ * Load and classify all providers from models.json.
+ * @returns {Object} map of provider name → { name, type, baseUrl, apiKey }
+ */
+export function getProviders() {
+  const modelsJson = JSON.parse(
+    readFileSync(`${homedir()}/.pi/agent/models.json`, 'utf-8')
+  );
+
+  const providers = {};
+  for (const [name, config] of Object.entries(modelsJson.providers)) {
+    const type = classifyProvider(name, config);
+    if (!type) continue;
+    providers[name] = {
+      name,
+      type,
+      baseUrl: config.baseUrl,
+      apiKey: config.apiKey || null,
+    };
+  }
+  return providers;
+}
+
+// Alias for backwards compatibility
+export const loadProviders = getProviders;