feat(api): implement API key management and authentication enhancements

- Added endpoints for managing API keys, including creation, retrieval, updating, and revocation.
- Introduced a new Auth session endpoint to retrieve current tenant and role information.
- Updated the authentication middleware to support API key-based authentication and track last used timestamps.
- Enhanced documentation to reflect new API key functionalities and usage guidelines.
- Improved logging for demo authentication scenarios.

migrations/sqlite/000013_api_key.down.sql

@@ -0,0 +1,3 @@
+DROP INDEX IF EXISTS idx_api_key_tenant_active;
+DROP INDEX IF EXISTS idx_api_key_token_hash;
+DROP TABLE IF EXISTS api_key;

migrations/sqlite/000013_api_key.up.sql

@@ -0,0 +1,19 @@
+CREATE TABLE api_key (
+    id           TEXT PRIMARY KEY,
+    tenant_id    TEXT NOT NULL REFERENCES tenant (id) ON DELETE CASCADE,
+    name         TEXT NOT NULL,
+    role         TEXT NOT NULL,
+    token_prefix TEXT NOT NULL,
+    token_hash   BLOB NOT NULL,
+    created_at   TEXT NOT NULL DEFAULT (strftime('%Y-%m-%dT%H:%M:%fZ', 'now')),
+    updated_at   TEXT NOT NULL DEFAULT (strftime('%Y-%m-%dT%H:%M:%fZ', 'now')),
+    expires_at   TEXT,
+    revoked_at   TEXT,
+    last_used_at TEXT,
+    CHECK (role IN ('viewer', 'editor', 'operator', 'node')),
+    CHECK (length(trim(name)) > 0),
+    CHECK (length(token_hash) = 32)
+);
+
+CREATE UNIQUE INDEX idx_api_key_token_hash ON api_key (token_hash);
+CREATE INDEX idx_api_key_tenant_active ON api_key (tenant_id) WHERE revoked_at IS NULL;