fix: resolve Sentry issues — JSONC config, ENOENT guard, Node.js port fallback, transient error filtering

[BYK]

Summary

Triages and resolves all 15 unresolved Sentry issues in LOREAI-GATEWAY. Fixes 3 real bugs and filters transient network noise.

Bug Fixes

GATEWAY-Y: .lore.json parse crash (Critical)

config.ts:260 — bare JSON.parse with no error handling. Users adding // comments to .lore.json (starting with /) crash the process.

Fix: Add inline stripJsonComments() for JSONC support (handles //, /* */, trailing commas) + wrap in try-catch to fall through to defaults on any parse failure.

GATEWAY-K: .lore.md ENOENT on every idle tick (Medium, 6472 events)

agents-file.ts:543 — exportLoreFile() calls writeFileSync without handling missing directories. When a project dir is deleted/renamed mid-session, the idle worker fires ENOENT every 30 seconds.

Fix: Wrap write+stat in try-catch, silently return on ENOENT. Other FS errors (EACCES, EIO) still propagate.

GATEWAY-6: Node.js EADDRINUSE bypass (Critical, 10 events, regressed)

node-polyfills.ts:88 — the Node.js serve() polyfill calls server.listen() which is async, but returns synchronously. EADDRINUSE is emitted as an 'error' event that nobody catches, completely bypassing the port fallback chain (3207 → 5673 → random).

Fix: Add a ready promise (listening/error events) to the polyfill, propagate through startServer() return type, and await server.ready in startGateway() so the existing catch block handles port conflicts correctly under Node.js. Includes:

• Unhandled rejection guard (ready.catch(() => {})) for callers that don't await
• Server cleanup (server.stop()) in the catch block to prevent FD leaks in multi-host configs

Sentry Noise Filtering

Added beforeSend to Sentry.init() to drop transient network errors that are expected in a long-running LLM proxy and not actionable:

• EPIPE / ECONNRESET / ECONNREFUSED
• Socket closed unexpectedly
• ZlibError
• TimeoutError: The operation timed out
• Worker upstream exhausted N retries (429, 502)

Each exception in the chain is tested independently so a real bug wrapping a transient cause isn't accidentally silenced.

Files Changed

File	Change
packages/core/src/config.ts	JSONC support + try-catch
packages/core/src/agents-file.ts	Silent ENOENT handling
packages/gateway/script/node-polyfills.ts	ready promise on serve() + unhandled rejection guard
packages/gateway/src/server.ts	Propagate ready? in return type
packages/gateway/src/cli/start.ts	await server.ready + server cleanup in catch
packages/gateway/script/bundle.ts	Updated type declarations
packages/gateway/instrument.ts	beforeSend transient error filter

Sentry Resolution

All 15 unresolved issues resolved:

• 3 bugs fixed (Y, K, 6)
• 8 transient errors now filtered (P, R, M, S, T, W, V, 4)
• 4 non-bugs resolved (X: test noise, G: caller error, N: user auth, Q: dup)