v0.2.0 reliability

Added

• New read tool get_server_info and matching resource hatchet://server/info, both
  delegating to a single _build_server_info helper and returning a byte-identical JSON
  payload (read_only, read_tool_count, mutating_tool_count, server_url_source —
  "token" or "override" —, hatchet_sdk_version, python_version). Neither surface
  carries the Hatchet token. Read tool count is now 25 (src/hatchet_mcp/tools/server_info.py,
  src/hatchet_mcp/resources.py).
• Per-call 30s deadline on every registered tool via asyncio.wait_for, so a hung Hatchet
  can no longer lock the stdio session (src/hatchet_mcp/_shared.py).
• Idempotent-only retry on transient 5xx, 429, and connection-class
  (RestTransportError) failures: 3 attempts, exponential backoff (1s / 2s / 4s with ±25%
  jitter), and Retry-After honored on 429 clamped to 10s. Non-idempotent mutations
  (trigger_workflow, push_event, cancel_runs, replay_runs, restore_task, every
  create_*) keep the deadline but skip the retry layer, gated at registration time by
  ToolAnnotations.idempotentHint (src/hatchet_mcp/_shared.py, src/hatchet_mcp/server.py).
• Structured stderr logging: one JSON-line record per tool invocation
  (event=tool.ok / tool.error, with tool, duration_ms, and a redacted redacted_error
  on failure) and per server lifecycle event (event=server.start / server.error). Records
  include input-validation failures that raise before any Hatchet call, because the timer
  starts at wrapper entry (src/hatchet_mcp/_logging.py).

Changed

• Startup banner is now an event=server.start JSON record on stderr instead of the
  unstructured hatchet-mcp: starting… print; the ConfigError exit emits a matching
  event=server.error record (src/hatchet_mcp/server.py).
• server.start / get_server_info use the same origin label "token" / "override" for
  the server URL source so a single grep covers both channels.
• Tool handlers no longer wrap each Hatchet call in try / except ApiException; the
  reliability wrapper owns the SDK-exception-to-RuntimeError translation centrally, and the
  raw exception flows through the retry layer first.

Security

• The stderr structured-log channel is independently redacted at format time — every string
  field, at any nesting depth, runs through redact() before emit. The existing MCP JSON-RPC
  error channel redaction via _api_error is unchanged; the two surfaces own independent
  redaction with neither acting as the other's gate (src/hatchet_mcp/_logging.py,
  src/hatchet_mcp/_shared.py).

Docs

• Freeze the v0.2.0/reliability spec and its paired ADR (Draft → Frozen, target → ga),
  and bump docs/roadmap/README.md's Status to v0.2.0.