fix(core): centralize time defaults

[realfishsam]

Summary

• Add shared core time utilities for timestamp unit detection and WebSocket reconnect defaults
• Standardize timestamp seconds/milliseconds heuristics across core and SDK server managers
• Standardize exchange WebSocket reconnect fallbacks on a shared 5s default and preserve explicit 0 values with nullish coalescing

Fixes #206
Fixes #225

Test Plan

• git diff --check
• python3 -m py_compile sdks/python/pmxt/server_manager.py
• npm run build --workspace=pmxt-core (attempted; tsc was killed by the local environment with exit 137)
• npx tsc --noEmit --pretty false --incremental false --skipLibCheck (attempted; killed by the local environment with exit 137)

[realfishsam]

PR Review: FAIL

What This Does

Centralizes reconnect/timestamp defaults across exchange WebSockets, normalizers, and SDK server-manager status conversion. This should be an internal cleanup with no intended SDK response-shape change.

Blast Radius

Core WebSocket clients for Gemini Titan, Kalshi, Limitless, Opinion, Probable; Polymarket/Probable normalizers; Python and TypeScript server-manager status helpers.

Consumer Verification

Before (base branch):
Base branch has duplicated literals such as 5000ms reconnect delays and local timestamp seconds/ms conversion. I could not run a consumer API comparison because the PR branch does not build.

After (PR branch):
PR branch fails before the sidecar can start: npm run build --workspace=pmxt-core reports src/exchanges/probable/websocket.ts(2,33): error TS2440: Import declaration conflicts with local declaration of 'QueuedPromise'.

Test Results

• Build: FAIL (npm run build --workspace=pmxt-core TypeScript error)
• Unit tests: NOT RUN (build failed)
• Server starts: FAIL (server not started because build failed)
• E2E smoke: FAIL (blocked by build failure)

Findings

1. core/src/exchanges/probable/websocket.ts:2 imports QueuedPromise from ../../types while the same file still declares local interface QueuedPromise<T> at line 7. TypeScript rejects the duplicate name, so the core package cannot build and the sidecar cannot ship.

PMXT Pipeline Check

• Field propagation (3-layer): N/A
• OpenAPI sync: N/A
• Financial precision: N/A
• Type safety: ISSUE — duplicate QueuedPromise declaration prevents compilation
• Auth safety: N/A

Semver Impact

patch -- intended internal cleanup, but currently unmergeable because it breaks the build.

Risk

No runtime behavior could be verified because the TypeScript build fails.

[realfishsam]

Pushed follow-up commits to repair the deterministic build blocker: removed the duplicate local QueuedPromise declaration in core/src/exchanges/probable/websocket.ts and refreshed generated API-doc metadata. Local validation passed: git diff --check, python3 -m py_compile sdks/python/pmxt/server_manager.py, npm run build --workspace=pmxt-core, and npm test --workspace=pmxt-core -- --runInBand --passWithNoTests (24 passed, 1 skipped). After other PRs landed, this PR is now conflicting again and the remaining CodeQL actions failure is an infra/auth error (Requires authentication), not a code finding.

[realfishsam]

PR Review: PASS (NOT VERIFIED)

What This Does

Centralizes timestamp conversion and reconnect default constants, then applies them across several exchange websocket/normalizer/fetcher paths and SDK server-manager uptime parsing. This reduces duplicated epoch-second/ms heuristics and reconnect magic numbers.

Blast Radius

Core websocket clients and timestamp normalizers for Gemini Titan, Kalshi, Limitless, Opinion, Polymarket, and Probable; Python and TypeScript server manager uptime parsing; generated API doc metadata timestamp only.

Consumer Verification

Before (base branch):
Different files used local timestamp thresholds (1e12, 10000000000, > 1e12) and reconnect defaults (1000 or 5000) directly.

After (PR branch):
Core paths use timestampToMs() / DEFAULT_RECONNECT_INTERVAL_MS from core/src/utils/time.ts, and SDK server managers use the same 10,000,000,000 threshold for lock-file timestamps. This is not directly observable through a simple sidecar HTTP call without mocked venue websocket/timestamp payloads.

Test Results

• Build: PASS (npm run build --workspace=pmxt-core)
• Core unit tests: PASS (24 suites / 644 tests passed; 1 suite / 3 tests skipped)
• Full npm test: FAIL in this checkout during Python SDK collection because pmxt_internal / eth_account are not available.
• Server starts: Not separately run for this PR
• E2E smoke: Not run against live websocket feeds

Findings

No blocking findings.

PMXT Pipeline Check

• Field propagation (3-layer): N/A
• OpenAPI sync: OK/N/A (only generated metadata timestamp changed)
• Financial precision: N/A
• Type safety: OK
• Auth safety: N/A

Semver Impact

patch -- internal utility/refactor with unchanged public response shape.

Risk

The Limitless websocket fallback reconnect delay changes from 1000ms to the shared 5000ms default; that seems intentional for consistency but was not validated against live feed recovery behavior.