Feat v0.3.1 instance assignment (#15)

Co-authored-by: Jeffrey Smith <jasafpro@gmail.com>
Co-committed-by: Jeffrey Smith <jasafpro@gmail.com>

server/database/migrations/sqlite/007_workflows.sql

@@ -69,3 +69,53 @@ CREATE TABLE IF NOT EXISTS workflow_versions (
 
 CREATE INDEX IF NOT EXISTS idx_workflow_versions_workflow
     ON workflow_versions(workflow_id, version_number);
+
+-- ── Workflow Instances (v0.3.1) ──────────────
+
+CREATE TABLE IF NOT EXISTS workflow_instances (
+    id                TEXT PRIMARY KEY,
+    workflow_id       TEXT NOT NULL REFERENCES workflows(id) ON DELETE CASCADE,
+    workflow_version  INTEGER NOT NULL,
+    current_stage     TEXT NOT NULL,
+    stage_data        TEXT NOT NULL DEFAULT '{}',
+    status            TEXT NOT NULL DEFAULT 'active'
+                          CHECK (status IN ('active', 'completed', 'cancelled', 'stale', 'error')),
+    started_by        TEXT NOT NULL,
+    entry_token       TEXT UNIQUE,
+    metadata          TEXT NOT NULL DEFAULT '{}',
+    stage_entered_at  TEXT NOT NULL DEFAULT (datetime('now')),
+    created_at        TEXT NOT NULL DEFAULT (datetime('now')),
+    updated_at        TEXT NOT NULL DEFAULT (datetime('now'))
+);
+
+CREATE INDEX IF NOT EXISTS idx_workflow_instances_workflow_status
+    ON workflow_instances(workflow_id, status);
+CREATE INDEX IF NOT EXISTS idx_workflow_instances_active
+    ON workflow_instances(status);
+
+CREATE TRIGGER IF NOT EXISTS workflow_instances_updated_at AFTER UPDATE ON workflow_instances
+    FOR EACH ROW WHEN NEW.updated_at = OLD.updated_at
+    BEGIN UPDATE workflow_instances SET updated_at = datetime('now') WHERE id = NEW.id; END;
+
+-- ── Workflow Assignments (v0.3.1) ────────────
+
+CREATE TABLE IF NOT EXISTS workflow_assignments (
+    id            TEXT PRIMARY KEY,
+    instance_id   TEXT NOT NULL REFERENCES workflow_instances(id) ON DELETE CASCADE,
+    stage         TEXT NOT NULL,
+    team_id       TEXT NOT NULL REFERENCES teams(id) ON DELETE CASCADE,
+    assigned_to   TEXT REFERENCES users(id) ON DELETE SET NULL,
+    status        TEXT NOT NULL DEFAULT 'unassigned'
+                      CHECK (status IN ('unassigned', 'claimed', 'completed', 'cancelled')),
+    review_data   TEXT NOT NULL DEFAULT '{}',
+    claimed_at    TEXT,
+    completed_at  TEXT,
+    created_at    TEXT NOT NULL DEFAULT (datetime('now'))
+);
+
+CREATE INDEX IF NOT EXISTS idx_workflow_assignments_instance_stage
+    ON workflow_assignments(instance_id, stage);
+CREATE INDEX IF NOT EXISTS idx_workflow_assignments_team_status
+    ON workflow_assignments(team_id, status);
+CREATE INDEX IF NOT EXISTS idx_workflow_assignments_assigned
+    ON workflow_assignments(assigned_to);