When the dashboard hits a DB connection timeout, users currently see a
raw error message with no
path forward. This PR adds an inline troubleshooting system that detects
known error types and
surfaces contextual next steps — restart the DB, read the docs, or debug
with AI.
## Changes
- New ErrorDisplay component (packages/ui-patterns) — styled error card
with a title, monospace error
block, optional troubleshooting slot, and a "Contact support" link that
always renders. Accepts
typed supportFormParams to pre-fill the support form.
- Error classification in handleError (data/fetchers.ts) — on every API
error, the message is tested
against ERROR_PATTERNS. If matched, handleError throws a typed subclass
(ConnectionTimeoutError
extends ResponseError) instead of a plain ResponseError. Stack traces
now show the exact error
class. All existing instanceof ResponseError checks continue to work.
- ErrorMatcher component — reads errorType from the thrown class
instance, does an O(1) lookup into
ERROR_MAPPINGS, and renders the matching troubleshooting accordion as
children of ErrorDisplay.
Falls back to plain ErrorDisplay for unclassified errors.
- Connection timeout mapping — first error type wired up, with three
troubleshooting steps: restart
the database, link to the docs, and "Debug with AI" (opens the AI
assistant sidebar with a
pre-filled prompt).
- Telemetry — three new typed events track when the troubleshooter is
shown, when accordion steps are
toggled, and which CTAs are clicked.
## Adding a new error type
1. Add a class to types/api-errors.ts
2. Add { pattern, ErrorClass } to data/error-patterns.ts
3. Create a troubleshooting component in errorMappings/
4. Add an entry to error-mappings.tsx
Charis