test: migrate behavioral tests and enforce 90% branch coverage

[jackhai9]

Replace legacy source-text regressions, method replacements, and fixed waits with executable behavior tests, and enforce the policy across the repository. The default complete coverage run now requires at least 90% branch coverage across all production sources and separately in each of seven critical orderbook modules.

Changes

• Migrate all 83 legacy Node test files and remove the seven method-replacement and 31 fixed-wait allowances. Map all 71 former orderbook source checks to current evidence while retaining metadata, distribution, and CSS contracts.
• Add strict test lint, explicit external-host contracts, deterministic clock/response boundaries, affected-test selection, and GitHub Actions integration.
• Merge actual Node and Chromium V8 execution back to all 82 production source files. Preserve raw captures, require complete passing runs, and give no branch credit to Chromium teardown calls that lack block evidence.
• Fix regressions exposed by the new behavior tests: retained depth wrappers after restoration, rate-limit cooldown parsing, precision observation, Stop availability, cancellation-list restoration, subtitle error handling, and duplicate/off-route automatic refreshes.
• Rebuild the affected installers: Orderbook 2.7.211 and m3u8 downloader 0.10.40; update the hand-maintained auto-refresh script to 1.0.11.

Local validation

Verified with Node 24.16.0:

Check	Result
Node and JSDOM	2,078 tests passed across 126 files
Chromium	364 scenarios passed: 357 production scenarios and seven collector proofs
Complete production branch coverage	9,179 / 10,184 branches, 90.13%
Seven critical-module branch gates	All passed, from 92.44% to 100%
Test lint, affected builds, syntax checks, and whitespace checks	Passed
Independent read-only reviews	Passed; no unresolved findings

The coverage percentage is a retained-evidence lower bound. No skipped or retried scenarios were accepted, and all 82 reported source hashes matched the workspace after collection.

Migration map · Coverage contract and measurements

All account, order, and media operations in these tests use offline fixtures. Live Binance, Tampermonkey installation, and media-site acceptance have not been performed.