fix: isolate channel startup failures

[artemgetmann]

Summary

• port upstream commit 30e80fb947 to keep gateway channel startup failures isolated per channel
• wrap startChannels() account startup in per-channel error handling so one broken channel does not block later channels from booting
• add a regression test proving a failing channel startup still allows the next channel to start
• carry the inherited doc-formatting fix required for pnpm check in this branch

Why

• this is a real availability fix: a single broken channel plugin or missing runtime module should not take out every later channel in gateway startup order
• the intake is lightweight and safe for the fork because the behavior change is narrow and the regression test pins it down

Validation

• pnpm test -- src/gateway/server-channels.test.ts
• pnpm build
• pnpm check

Risk

• low: startup behavior only changes when one channel throws during boot
• low: failure logging stays channel-scoped and later channels continue to start
• medium: this PR includes the same inherited docs formatting fix already needed on the other intake branches so repo-wide check can pass