[godronus]

Summary

Adds the gcore:db@0.1.0 package (customer-owned databases bound to an app by name), synchronous SQL for the MVP:

• deps/db/sql-types.wit: value, column, query-result, statement, db-error, error
• deps/db/sql-sync.wit: resource database { open(name), query(sql, params), batch(statements) }, blocking
• world reactor imports gcore:db/sql-sync@0.1.0

Contract is PostgreSQL ($1 placeholders, SQLSTATE codes). Each query auto-commits; each batch is one transaction. Full design and rationale: docs/db/ in G-Core/FastEdge (branch feat/db-interface).

Decisions needed

#	Decision	Proposal
1	Naming	sql-types + sql-sync, following cache-types / cache-sync; the plain name sql is reserved for the async interface (draft PR stacked on this one)
2	Package	Separate package gcore:db, not gcore:fastedge, so DB connectors version independently; KV (Upstash) will follow as gcore:db/kv, distinct from Edge Storage key-value
3	value typing	Narrowest lossless variant (int8 → int64, numeric → decimal text, json/jsonb → JSON text, bytea → bytes, other types → Postgres text + type-oid)
4	Error variant	no-such-database, access-denied, config, connection, timeout, limit, query, internal-error

Merge this first: the engine vendors these files and both SDKs pin this branch as a submodule.

Related: G-Core/FastEdge#659, G-Core/FastEdge-sdk-rust#93, G-Core/FastEdge-sdk-js#155 · Async (stacked): #9

[Copilot]

🟡 Changes recommended

The batch failure contract needs clarification to prevent unsafe retries when the commit outcome is unknown.

1 open issue

• Clarify rollback guarantee and unknown commit outcome on timeout · New

What changed in this PR

Adds a synchronous PostgreSQL-compatible database interface and makes it available to components through the reactor world.

Changes:

• Defines database bindings, parameterized queries, and transactional batches.
• Adds SQL value types, result metadata, and structured errors.
• Imports gcore:db/sql@0.1.0 into the reactor world.

File	Description
world.wit	Imports the new SQL interface.
deps/​db/​sql.wit	Defines the database API, types, errors, and behavioral contract.

_{Review effort: Balanced}