feat(dev): log the failing procedure in a tRPC batch

[iscekic]

The problem

A batched tRPC call answers 207 when one of its procedures fails, and folds that
failure into the response body. apps/web/src/app/api/trpc/[trpc]/route.ts passed
fetchRequestHandler only endpoint and createContext, with no onError hook,
so nothing reached the server log.

An operator saw this and nothing else:

POST /api/trpc/organizations.securityAgent.getPermissionStatus,organizations.securityAgent.getConfig,
organizations.securityAgent.getRepositories,organizations.securityAgent.listFindings?batch=1 207 in 78ms

Four procedures, one of them failing, and no way to tell which or why.

What it cost

mobile-ui-repairs-63e7 spent most of a night on one screen showing
Could not load Security Agent. It ruled out, with evidence:

• the data — the organization finding row exists and is correct;
• authorization — all four procedures are organizationMemberProcedure, and the log
  records Access granted, calling next four times before the batch;
• preconditions — each of the four handlers tolerates an absent integration,
  configuration, repository, or remediation row.

Three classes eliminated, and the cause is still unknown, because the error itself is
never printed. The screen remains unproved.

The change

Ten lines. onError logs the procedure type, its path, and the error code and message.

Development only: process.env.NODE_ENV === 'development', matching the convention in
lib/constants.ts and lib/account-linking-session.ts. Production reporting is
unchanged and gains no log line.

For other orchestrators

Any section that hits an opaque 207 can cherry-pick dev/trpc-batch-onerror into its
worktree to see the failing procedure, without waiting for this to merge.

Checks

• pnpm --filter @kilocode/web run typecheck — exit 0, no errors.
• oxfmt applied; the file is clean.
• The callback parameters are inferred from HTTPErrorHandlerOptions, so the signature
  cannot drift from @trpc/server.

[kilo-code-bot]

Code Review Summary

Status: No Issues Found | Recommendation: Merge

Files Reviewed (2 files)

• apps/web/src/app/api/trpc/[trpc]/route.ts
• apps/web/src/app/api/trpc/[trpc]/route.test.ts

Previous Review Summaries (2 snapshots, latest commit f54446c)

Current summary above is authoritative. Previous snapshots are kept for context only.

Previous review (commit f54446c)

Status: No Issues Found | Recommendation: Merge

Files Reviewed (1 files)

• apps/web/src/app/api/trpc/[trpc]/route.ts

Previous review (commit 9677c81)

Status: No Issues Found | Recommendation: Merge

Files Reviewed (1 files)

• apps/web/src/app/api/trpc/[trpc]/route.ts

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_{Review guidance: REVIEW.md from base branch main}