feat(connect): extract the connector wire contract into packages/connect-contract (#2179)

* feat(connect): extract the connector wire contract into packages/connect-contract

The definitions in lib/connect/contract.ts (key prefix, headers, entitlements
path, entitlement and sync-report shapes) move into a standalone MIT package,
packages/connect-contract (published as @accounted/connect-contract), joined
by the error envelope, the stable error codes, and Zod schemas for every
Peppol connector operation (lookup, submit, status, evidence, register,
unregister, inbound list and xml) with an operation table. Shape only: no
behaviour, no provider code. In-repo callers import through the tsconfig and
vitest alias; lib/connect/contract.ts re-exports so nothing else changes.
The point of the package is that either side of the connection can be built
outside this repository: a self-hosted ledger talking to Accounted Connect,
or another connector service talking to the open ledger.

Co-Authored-By: Claude Fable 5.1 <noreply@anthropic.com>
Signed-off-by: Jakob Wennberg <311770904+jakobwennberg-oss@users.noreply.github.com>

* docs(decisions): record the Connect direction, the Peppol proxy shape, and the contract package

Co-Authored-By: Claude Fable 5.1 <noreply@anthropic.com>
Signed-off-by: Jakob Wennberg <311770904+jakobwennberg-oss@users.noreply.github.com>

---------

Signed-off-by: Jakob Wennberg <311770904+jakobwennberg-oss@users.noreply.github.com>
Co-authored-by: Jakob Wennberg <311770904+jakobwennberg-oss@users.noreply.github.com>
Co-authored-by: Claude Fable 5.1 <noreply@anthropic.com>

DECISIONS.md

@@ -1505,3 +1505,6 @@ One line per decision: `[YYYY-MM-DD] <decision>: <why>`. Appended by agents and
 [2026-09-02] parties children/roles reference parties(id, company_id) with composite FKs, not parties(id): a party UUID from another tenant is rejected by construction instead of relying on each writer to check; ON DELETE SET NULL (party_id) on customers/suppliers because a plain SET NULL would null company_id too (Superagent P2 on #2162)
 [2026-09-02] Party suggestions attach only by explicit party_id, org number or an exact ledger key already in alias_keys; same-core text is reported as similar_to for a person to decide and identities are withheld when a key mixes org numbers: the selection eval measured 9% false merges on trade names shared by distinct legal entities (Fortnox AB / Fortnox Finans), so text never merges
 [2026-09-02] Edited migration 20260902160000 after merge: its backfill failed on prod (ensure_party: name is required; 3 nameless rows) so it was never applied there, the Supabase main branch sat in MIGRATIONS_FAILED and every later migration was blocked behind it. An unapplied file is not a shipped schema; a follow-up migration could not run before it
+[2026-09-02] Accounted Connect direction (founder decision after a fork was resold): the ledger stays AGPL with no licence change and no ee/ split; provider integration logic moves behind the connector (hosted app/api/connect/* today, a separate Connect service later) one upstream at a time on the existing connector keys, ledger and entitlement sync. Rejected: FSL/BSL relicensing (58 public forks keep the AGPL version; DCO-only contributions cannot be relicensed without consent) and closed first-party extensions alone (the code still ships to every self-hoster, and the provider extensions do not honour the Extension API boundary).
+[2026-09-02] Peppol connector proxy (#2177) is operation-shaped (lookup/submit/status/evidence/recipient/inbound), NOT a path passthrough like the bank proxy: Qvalia URLs embed Arcim's partner and account numbers, the account is shared by every hosted company and every instance so reads must be scoped to what the caller owns, and Qvalia's inbound "read" endpoint marks documents read for the whole account. Ownership is bound to (key, company_ref); participants a key may publish are recorded on the key at issuance (connector_keys.peppol_participants) because the hosted side cannot otherwise know which organisations an instance legitimately hosts. Inbound is served from the hosted archive, never by calling Qvalia on the instance's behalf.
+[2026-09-02] The connector wire contract is an MIT package (packages/connect-contract, @accounted/connect-contract) consumed in-repo from source through a tsconfig/vitest alias (#2179), and check:guards ratchets the set of files naming a provider API host (#2178): the open repo keeps the contract and the manual file paths, either side of the connection can be implemented outside it, and the grandfathered provider-host set may only shrink. Declined a NOT VALID + later VALIDATE pair for the ledger service CHECK: connector_connections has zero prod rows until keys are issued.