2.22.0

This release makes CodeGem more reliable with Gemini and adds support for Gemini 4 Argon.

Fixed

• Retry CodeGem Gemini requests on HTTP 429 and 5xx and on transient
  network errors, with bounded exponential backoff and jitter. Google's
  RetryInfo delay and Retry-After are honoured. Attempts are configurable
  with max_attempts, retry_initial_delay and retry_max_delay, logged per
  attempt, and included in the final error message.
• Stop forcing a high thinking level on Gemini 3 models. CodeGem now leaves
  Google's per-model default in place, accepts low, medium and high for
  Gemini 4 Argon through the normal reasoning setting, and rejects levels a
  model does not document, such as minimal on Argon, with the supported list.
  An explicit thinking_config still wins.
• Prepare CodeGem for Gemini 4 Argon: a 20 minute default timeout, the
  documented medium thinking level, and long decode within the 32,768 token
  non-streaming request cap. CONTINUATION hops are joined
  into one signed model turn, and a MAX_TOKENS reply with a continuation
  token resumes with a higher limit up to max_output_tokens_ceiling.
• Handle Gemini finish reasons explicitly. A malformed function call or an
  empty candidate is retried once. Safety, recitation, blocklist and blocked
  prompts report a readable reason. Unknown response parts are skipped instead
  of ending the turn, and are replayed exactly with their thought signatures.
• Stop sending temperature, top_p, top_k and candidate_count to
  Gemini 4 Argon, which Google documents as ignoring sampling parameters. A
  configured value is dropped with a one-time warning. Local Gemma keeps its
  sampling settings.
• Never send thinkingBudget to Gemini 4, or together with thinkingLevel to
  any model. A raw thinking_config with both keeps the level and warns.
• Make the Windows MCP panel test poll for the detail text instead of
  asserting after a single pause.
• Make the Windows theme install test poll the worker instead of cancelling it
  on timeout, so it runs on Windows again rather than being skipped.

Changed

• Retire the deprecated gemini-3.7-flash and gemini-3.5-flash from the
  Google catalog and pickers. Saved configs naming them are mapped to
  gemini-3.8-flash and gemini-3.6-flash with a notice.