Harden scheduler Node 22/24/26 and wrapper dispatch paths

[amittell]

Summary

• Supports Node 22, 24, and 26 in package engines, install docs, README, and the GitHub Actions CI matrix.
• Keeps better-sqlite3 on ^12.10.0 so the native binding supports the Node 26 ABI.
• Fixes branded dispatch/chilisaus scheduler CLI resolution by falling back from wrapper-local paths to the deployed packaged scheduler CLI.
• Avoids new persistent monitor jobs embedding versioned Homebrew Cellar Node paths or branded wrapper index.mjs paths when the packaged scheduler dispatch scripts are available, while preserving branded config/state via env vars.
• Tightens the dispatcher startup replay test to wait for the orphaned run to reach crashed, fixing the macOS Node 22 CI race exposed by the expanded matrix.

Validation

• node --version: v26.0.0; npm --version: 11.12.1.
• npm ci passed under Node 26. npm reported one existing moderate audit finding.
• node --check dispatch/index.mjs && node --check dispatch/529-recovery.mjs && node --check tests/delivery-fixes.test.mjs passed.
• npm run verify:local passed under Node 26: lint, typecheck, npm test (1768 passed, 0 failed), coverage (1768 passed, 0 failed, critical module thresholds passed), and pack.
• node --test tests/delivery-fixes.test.mjs passed (13 passed, 0 failed).
• npm run lint passed after the standalone test assertion adjustment and again after the dispatcher replay test-race fix.
• npm test passed after the dispatcher replay test-race fix (1768 passed, 0 failed).

Host Verification

• mac-mini (mac-mini.lan): Node v26.0.0; command -v node is /opt/homebrew/bin/node; process.execPath is /opt/homebrew/Cellar/node/26.0.0/bin/node. Verified /Users/alexm/.openclaw/chilisaus/index.mjs and 529-recovery.mjs with node --check, verified /Users/alexm/.openclaw/packages/openclaw-scheduler/node_modules/openclaw-scheduler/cli.js exists and passes node --check, and confirmed the live chilisaus files contain resolveSchedulerCliPath with OPENCLAW_SCHEDULER_CLI / SCHEDULER_CLI fallbacks. The live chilisaus checkout already has local modifications/untracked synced files; I only inspected it and did not alter that checkout.
• mini-beast (ssh alex@mini-beast.lan): reachable. Node v22.20.0; command -v node is /usr/bin/node; process.execPath is /usr/bin/node-22. No ~/.openclaw root, ~/.openclaw/chilisaus, packaged scheduler CLI, or scheduler/chilisaus process was present to validate on that host.

CI

• Initial PR run started all six Node/OS jobs; five passed and macOS Node 22 exposed the dispatcher replay test race fixed in the latest commit.
• Latest CI run for cb511f1cdfab97cc2128fe4ebae7947a5097a813 passed all six jobs: Ubuntu and macOS on Node 22, 24, and 26.

Caveats

• I did not deploy this source change into the live mac-mini wrapper/package; this PR carries the source fix. The existing live chilisaus checkout was left untouched.