fix(translator): ESM-safe registry + tool-id pairing + responses max_tokens; add real-creds tests

- translator/index.js: replace require() with static side-effect imports (ESM-safe),
  lazy-init registry maps to survive circular import order
- openai-responses->openai: map max_output_tokens -> max_tokens (avoid leaking field upstream)
- gemini/antigravity -> openai: derive deterministic tool_call id from name so
  functionCall/functionResponse pair correctly (fixes provider tool-pairing 400s)
- add offline unit tests (finish-reason, usage, session-manager, ollama malformed args, const guard)
- add real-creds integration tests (provider-cases + all-formats matrix: 6 inbound formats x 4 scenarios)

Includes co-located provider registry refactor (pricing/capabilities/media providers) and sessionManager updates.

Co-authored-by: Cursor <cursoragent@cursor.com>

tests/__baseline__/current.json

@@ -1 +1 @@
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+{"numTotalTestSuites":276,"numPassedTestSuites":259,"numFailedTestSuites":17,"numPendingTestSuites":0,"numTotalTests":840,"numPassedTests":788,"numFailedTests":26,"numPendingTests":26,"numTodoTests":0,"snapshot":{"added":0,"failure":false,"filesAdded":0,"filesRemoved":0,"filesRemovedList":[],"filesUnmatched":0,"filesUpdated":0,"matched":99,"total":99,"unchecked":0,"uncheckedKeysByFile":[],"unmatched":0,"updated":0,"didUpdate":false},"startTime":1781497742906,"success":false,"testResults":[{"assLine truncated