fix(cli): an unreadable registry says so instead of crashing

[blafourcade]

What

aidd marketplace list died with

Error: Cannot read properties of undefined (reading 'map')

on a ~/.config/aidd/marketplaces.json holding {"version":1} — a real file, found while clearing test residue out of a machine's own configuration.

MarketplaceRegistryAdapter.read caught a missing file and nothing else. JSON.parse could throw, and parsed.marketplaces could be undefined, so a present-but-malformed registry reached .map() and produced a stack trace naming nothing a person can act on. Invalid JSON gave the same shape of answer, in the parser's words rather than the tool's.

Why not read it as empty

That would be worse than crashing. save() reads this same list, appends to it and writes the whole file back — so one silent empty read turns a file with five marketplaces into a file with one.

A missing file is a different answer and keeps its own: no file, no marketplaces, nothing to lose.

Behaviour, verified on the built binary

marketplaces.json	before	after
absent	No marketplaces registered.	unchanged
{"version":1,"marketplaces":[]}	No marketplaces registered.	unchanged
{"version":1}	Cannot read properties of undefined (reading 'map')	Cannot read the marketplace registry at <path>: it carries no \marketplaces` list. Repair the file, or delete it to start from an empty registry.`
not json	Unexpected token 'o', "not json" is not valid JSON	same sentence, the parser's reason inside it, the path named

Tests

Three added to marketplace-registry-adapter.integration.test.ts. The two for the malformed states were red first, for the reason they name:

→ expected [Function] to throw error including '/var/folders/…/marketplaces.json'
  but got 'Cannot read properties of undefined (…'
→ expected [Function] to throw error including '/var/folders/…/marketplaces.json'
  but got 'Unexpected token \'o\', "not json" is…'

The third — a present, empty list still reading as an empty registry — passed before and after, and is there so the fix cannot be mistaken for "any unusual file is an error".

Gates

• cli vitest — 3507/3507
• node --test "scripts/__tests__/**/*.test.js" — 380/380
• knip --production --exclude exports,types — exit 0
• biome check src tests — the only two warnings are pre-existing, in a file this branch does not touch

🤖 Generated with Claude Code

https://claude.ai/code/session_01VWNxk63AGKkqE8HRqHLjGp

[blafourcade]

Rebuilt after CI: the three red jobs were all one failure — pnpm build running check-bundle-size.mjs before the tests.

Bundle size: 601.3 KB / budget: 601 KB
FAIL: bundle exceeds budget (601.3 KB > 601 KB)

Measured on this branch: next builds at 600.7 KB against a 601 KB budget — 0.3 KB of headroom, less than this fix costs.

Trimmed what could be trimmed first (the named error class became a plain Error from a helper: 601.3 → 601.2 KB), then raised the budget to 603 KB and recorded the measurement in the script's own ledger, the way the four raises before it did. Its comment asks for exactly that: "The budget exists to make growth visible, not to be a wall: it is raised deliberately when a feature earns it, and the raise is what a reviewer sees."

Green locally: 3507/3507 cli, 380/380 scripts, knip exit 0, biome clean, OK: within budget.