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/anthropic-teams.js

@@ -0,0 +1,130 @@
+/**
+ * anthropic-teams.js — Unified schema parser for Anthropic Teams direct providers.
+ *
+ * Teams providers (team-vigilio, team-ludo, team-molto, team-nadja, team-buio) use the
+ * anthropic-ratelimit-unified-* header family. Headers are present on EVERY response
+ * (200 and 429). A 429 is expected when the 7d budget is exhausted and contains valid
+ * quota data — do not treat it as an error, extract the headers normally.
+ *
+ * Header reference (from Face's recon, issue trentuna/a-team#91):
+ *   anthropic-ratelimit-unified-status            allowed|rejected
+ *   anthropic-ratelimit-unified-5h-status         allowed|rejected
+ *   anthropic-ratelimit-unified-5h-utilization    0.0–1.0
+ *   anthropic-ratelimit-unified-5h-reset          Unix timestamp
+ *   anthropic-ratelimit-unified-7d-status         allowed|rejected
+ *   anthropic-ratelimit-unified-7d-utilization    0.0–1.0
+ *   anthropic-ratelimit-unified-7d-reset          Unix timestamp
+ *   anthropic-ratelimit-unified-7d-surpassed-threshold  (present only when maxed)
+ *   anthropic-ratelimit-unified-representative-claim  five_hour|seven_day
+ *   anthropic-ratelimit-unified-fallback-percentage   0.0–1.0
+ *   anthropic-ratelimit-unified-reset             Unix timestamp (binding reset)
+ *   anthropic-ratelimit-unified-overage-status    rejected
+ *   anthropic-ratelimit-unified-overage-disabled-reason  org_level_disabled
+ *   anthropic-organization-id                     UUID
+ *   retry-after                                   seconds (only on 429)
+ */
+
+import { getSeverity } from '../report.js';
+
+/**
+ * Parse unified rate-limit headers from a Teams API response.
+ *
+ * @param {Object} headers — fetch Response.headers (or compatible mock with .get(name))
+ * @param {number} httpStatus — HTTP status code of the response
+ * @param {string} providerName — name for logging/context
+ * @returns {Object} normalized provider result
+ */
+export function parseTeamsHeaders(headers, httpStatus, providerName) {
+  const h = (name) => headers.get(name);
+
+  // 401 = invalid API key — no quota data available
+  if (httpStatus === 401) {
+    return {
+      type: 'teams-direct',
+      status: 'invalid_key',
+      utilization_5h: null,
+      utilization_7d: null,
+      severity: 'unknown',
+    };
+  }
+
+  const status = h('anthropic-ratelimit-unified-status') || (httpStatus === 429 ? 'rejected' : 'allowed');
+  const util5h = parseFloat(h('anthropic-ratelimit-unified-5h-utilization'));
+  const util7d = parseFloat(h('anthropic-ratelimit-unified-7d-utilization'));
+  const resetTs = parseInt(h('anthropic-ratelimit-unified-reset'), 10);
+  const retryAfter = h('retry-after') ? parseInt(h('retry-after'), 10) : null;
+
+  // Compute reset_in_seconds from the binding reset Unix timestamp
+  const nowSec = Math.floor(Date.now() / 1000);
+  const resetInSeconds = !isNaN(resetTs) ? Math.max(0, resetTs - nowSec) : null;
+
+  const result = {
+    type: 'teams-direct',
+    status,
+    utilization_5h: isNaN(util5h) ? null : util5h,
+    utilization_7d: isNaN(util7d) ? null : util7d,
+    representative_claim: h('anthropic-ratelimit-unified-representative-claim') || null,
+    reset_timestamp: isNaN(resetTs) ? null : resetTs,
+    reset_in_seconds: resetInSeconds,
+    organization_id: h('anthropic-organization-id') || null,
+    // Additional detail headers
+    status_5h: h('anthropic-ratelimit-unified-5h-status') || null,
+    status_7d: h('anthropic-ratelimit-unified-7d-status') || null,
+    overage_status: h('anthropic-ratelimit-unified-overage-status') || null,
+    fallback_percentage: h('anthropic-ratelimit-unified-fallback-percentage')
+      ? parseFloat(h('anthropic-ratelimit-unified-fallback-percentage'))
+      : null,
+  };
+
+  // Include retry_after_seconds only when present (429 responses)
+  if (retryAfter !== null) {
+    result.retry_after_seconds = retryAfter;
+  }
+
+  // Include surpassed threshold when present (maxed budget)
+  const surpassed = h('anthropic-ratelimit-unified-7d-surpassed-threshold');
+  if (surpassed !== null) {
+    result.surpassed_threshold_7d = parseFloat(surpassed);
+  }
+
+  result.severity = getSeverity(result);
+  return result;
+}
+
+/**
+ * Probe a single Teams provider by making a minimal API call.
+ * Extracts headers regardless of whether the response is 200 or 429.
+ *
+ * @param {string} providerName
+ * @param {string} baseUrl
+ * @param {string} apiKey
+ * @returns {Promise<Object>} normalized provider result
+ */
+export async function probeTeamsProvider(providerName, baseUrl, apiKey) {
+  try {
+    const response = await fetch(`${baseUrl}/v1/messages`, {
+      method: 'POST',
+      headers: {
+        'x-api-key': apiKey,
+        'anthropic-version': '2023-06-01',
+        'content-type': 'application/json',
+      },
+      body: JSON.stringify({
+        model: 'claude-haiku-4-5-20251001',
+        max_tokens: 1,
+        messages: [{ role: 'user', content: 'Hi' }],
+      }),
+    });
+
+    return parseTeamsHeaders(response.headers, response.status, providerName);
+  } catch (err) {
+    return {
+      type: 'teams-direct',
+      status: 'error',
+      message: err.message,
+      utilization_5h: null,
+      utilization_7d: null,
+      severity: 'unknown',
+    };
+  }
+}