/**
 * @fileoverview Migration v16 — add `source` column + extend `trust_tier` CHECK
 * @see SMI-4665: Filesystem-walking SKILL.md import command
 *
 * Adds two changes to the `skills` table:
 *
 *  1. `source TEXT NOT NULL DEFAULT 'registry' CHECK (source IN ('registry', 'local'))`
 *     — distinguishes registry-synced rows from filesystem-imported rows so
 *     `sync --force` can refuse to clobber locally-imported skills.
 *
 *     NOTE: Migration v2 (SMI-974) added a free-form `source TEXT` column that
 *     held values like `'github'` for Phase-5 imports. The v16 recreation
 *     coerces any non-`'local'` legacy value to `'registry'` so the new CHECK
 *     constraint accepts existing rows. The semantic shift is intentional —
 *     callers that need the original import-source string can rely on
 *     `repo_url` (always set for github-sourced rows). See SMI-4665 retro.
 *
 *  2. Extend the `trust_tier` CHECK to allow `'local'`. Existing values:
 *     `verified`, `community`, `experimental`, `unknown`. Local skills
 *     surface as a distinct tier in search output instead of being indistinguishable
 *     from unscanned registry imports under `'unknown'`.
 *
 * SQLite cannot ALTER an existing CHECK constraint in place — the table is
 * recreated using the standard rename/copy/drop dance, all wrapped in a
 * transaction so a mid-process kill leaves either the old shape or the new
 * shape, never a half-applied state.
 *
 * Idempotent: short-circuits when the `source` column already exists. Re-running
 * the migration on a v16+ DB is a no-op. The duplicate-column guard in
 * `runMigrations` / `runMigrationsSafe` adds defense-in-depth.
 */
import type { Database } from '../database-interface.js';
/**
 * Apply the v16 migration if not already present.
 *
 * Exported as a function rather than a SQL string because the table-recreation
 * dance must short-circuit on an already-migrated DB (the canonical schema
 * already includes `source` for fresh installs).
 */
export declare function applyMigrationV16(db: Database): void;
//# sourceMappingURL=v16-skill-source.d.ts.map