Operation protocol and runtime adapters

Context

Desktop uses native SQLite. Future web may use SQLite WASM. UI behavior must not import Tauri or database details.

Decision

UI submits versioned WorkspaceOperation values through a small WorkspaceStorage port. Every adapter passes the same contract tests.

Consequences

• Runtime choice stays local.
• Operations can later feed sync/outbox systems.
• Adapter implementations duplicate some storage mechanics but not product semantics.
• Adapter-independent validation executes before database-dependent validation.
• Schema version changes require explicit compatibility work.