Empty catch blocks hide errors in cleanup operations #18239

Description

Several catch blocks in the codebase are empty, silently ignoring errors during cleanup operations (killing processes, destroying services). This makes debugging difficult when cleanup fails.

Affected Files

• packages/opencode/src/mcp/index.ts:232 - Killing MCP descendant processes
• packages/opencode/src/pty/index.ts:99, 232 - Killing PTY processes
• packages/opencode/src/server/mdns.ts:40 - Destroying bonjour instance

Current Behavior

try {
  process.kill(dpid, "SIGTERM")
} catch {}  // Error is completely hidden

Expected Behavior

These errors should be logged at debug level so developers can see what's happening during cleanup, even when failures are expected (e.g., process already exited).

Proposed Solution

Add debug logging to these catch blocks:

try {
  process.kill(dpid, "SIGTERM")
} catch (err) {
  log.debug("Failed to kill descendant process", { pid: dpid, error: err })
}

Impact

• Low impact: These are cleanup operations where failures are often expected
• Improves debuggability during development
• Follows better error handling practices