v0.7.0 — Production hardening

[AnthonyPuggs]

Summary

The MCP server is now a better open-data citizen, observable, and resilient across process restarts.

Added

• Identified User-Agent on all outgoing ABS/RBA requests, so upstream operators can identify callers.
• Structured JSON logging to stderr covering request start/success, retries, parse failures, cache
  events, and stale fallbacks. Controlled by AUSECON_LOG_LEVEL (default INFO; DEBUG opts into cache
  events). stdio transport's stdout stays untouched.
• Persistent dual-layer cache (memory + disk) via platformdirs. Survives uvx process restarts,
  so the first call of every session no longer pays full upstream latency. Atomic writes, schema-versioned
  JSON, self-healing on corruption.
• stale-if-error fallback: if upstream fails and a cached payload exists on disk, return it with
  metadata.stale = true, cached_at, and expires_at. Parse errors still raise — upstream shape drift
  stays loud.
• metadata.server_version stamped on every data response for reproducible bug reports.
• Nightly integration suite (.github/workflows/integration.yml) hitting real ABS and RBA endpoints
  on a cron. On failure, upserts a single open upstream-drift issue instead of spamming duplicates.

New environment variables

• AUSECON_CACHE_DIR — override cache directory (default: OS-appropriate user cache dir).
• AUSECON_CACHE_DISABLED=1 — disable all caching (memory + disk).
• AUSECON_LOG_LEVEL — logging verbosity (INFO default).

Dependencies

• Added platformdirs>=4.0,<5 as a direct dependency.

Internal

• New src/ausecon_mcp/logging.py (idempotent configure_logging, JSON formatter, stderr-only).
• New src/ausecon_mcp/providers/_http.py (shared UA client + version resolver).
• TTLCache rewritten to dual-layer with unified wall-clock expiry and get_stale(); disk I/O errors
  never surface to callers.
• Retry layer now logs request.retry / request.failed with attempt counts and durations.

Verification

• 121 unit tests pass; ruff clean.
• Nightly workflow dispatched manually to confirm green before merge.

Full changelog: v0.6.0...v0.7.0

---

This discussion was created from the release v0.7.0 — Production hardening.