Checkpoint: password reset, rule expiry, migrations

- Self-service and admin password-change endpoints
  (PUT /v1/auth/password, PUT /v1/accounts/{id}/password)
- Policy rule time-scoped expiry (not_before / expires_at)
  with migration 000006 and engine filtering
- golang-migrate integration; embedded SQL migrations
- PolicyRecord fieldalignment lint fix

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

openapi.yaml

@@ -206,6 +206,24 @@ components:
         enabled:
           type: boolean
           example: true
+        not_before:
+          type: string
+          format: date-time
+          nullable: true
+          description: |
+            Earliest time the rule becomes active. NULL means no constraint
+            (always active). Rules where `not_before > now()` are skipped
+            during evaluation.
+          example: "2026-04-01T00:00:00Z"
+        expires_at:
+          type: string
+          format: date-time
+          nullable: true
+          description: |
+            Time after which the rule is no longer active. NULL means no
+            constraint (never expires). Rules where `expires_at <= now()` are
+            skipped during evaluation.
+          example: "2026-06-01T00:00:00Z"
         created_at:
           type: string
           format: date-time
@@ -582,6 +600,68 @@ paths:
         "401":
           $ref: "#/components/responses/Unauthorized"
 
+  /v1/auth/password:
+    put:
+      summary: Change own password (self-service)
+      description: |
+        Change the password of the currently authenticated human account.
+        The caller must supply the correct `current_password` to prevent
+        token-theft attacks: possession of a valid JWT alone is not sufficient.
+
+        On success:
+        - The stored Argon2id hash is replaced with the new password hash.
+        - All active sessions *except* the caller's current token are revoked.
+        - The lockout failure counter is cleared.
+
+        On failure (wrong current password):
+        - A login failure is recorded against the account, subject to the
+          same lockout rules as `POST /v1/auth/login`.
+
+        Only applies to human accounts. System accounts have no password.
+      operationId: changePassword
+      tags: [Auth]
+      security:
+        - bearerAuth: []
+      requestBody:
+        required: true
+        content:
+          application/json:
+            schema:
+              type: object
+              required: [current_password, new_password]
+              properties:
+                current_password:
+                  type: string
+                  description: The account's current password (required for verification).
+                  example: old-s3cr3t
+                new_password:
+                  type: string
+                  description: The new password. Minimum 12 characters.
+                  example: new-s3cr3t-long
+      responses:
+        "204":
+          description: Password changed. Other active sessions revoked.
+        "400":
+          $ref: "#/components/responses/BadRequest"
+        "401":
+          description: Current password is incorrect.
+          content:
+            application/json:
+              schema:
+                $ref: "#/components/schemas/Error"
+              example:
+                error: current password is incorrect
+                code: unauthorized
+        "429":
+          description: Account temporarily locked due to too many failed attempts.
+          content:
+            application/json:
+              schema:
+                $ref: "#/components/schemas/Error"
+              example:
+                error: account temporarily locked
+                code: account_locked
+
   # ── Admin ──────────────────────────────────────────────────────────────────
 
   /v1/auth/totp:
@@ -984,7 +1064,10 @@ paths:
         `token_issued`, `token_renewed`, `token_revoked`, `token_expired`,
         `account_created`, `account_updated`, `account_deleted`,
         `role_granted`, `role_revoked`, `totp_enrolled`, `totp_removed`,
-        `pgcred_accessed`, `pgcred_updated`.
+        `pgcred_accessed`, `pgcred_updated`, `pgcred_access_granted`,
+        `pgcred_access_revoked`, `tag_added`, `tag_removed`,
+        `policy_rule_created`, `policy_rule_updated`, `policy_rule_deleted`,
+        `policy_deny`.
       operationId: listAudit
       tags: [Admin — Audit]
       security:
@@ -1118,6 +1201,57 @@ paths:
         "404":
           $ref: "#/components/responses/NotFound"
 
+  /v1/accounts/{id}/password:
+    parameters:
+      - name: id
+        in: path
+        required: true
+        schema:
+          type: string
+          format: uuid
+        example: 550e8400-e29b-41d4-a716-446655440000
+
+    put:
+      summary: Admin password reset (admin)
+      description: |
+        Reset the password for a human account without requiring the current
+        password. This is intended for account recovery (e.g. a user forgot
+        their password).
+
+        On success:
+        - The stored Argon2id hash is replaced with the new password hash.
+        - All active sessions for the target account are revoked.
+
+        Only applies to human accounts. The new password must be at least
+        12 characters.
+      operationId: adminSetPassword
+      tags: [Admin — Accounts]
+      security:
+        - bearerAuth: []
+      requestBody:
+        required: true
+        content:
+          application/json:
+            schema:
+              type: object
+              required: [new_password]
+              properties:
+                new_password:
+                  type: string
+                  description: The new password. Minimum 12 characters.
+                  example: new-s3cr3t-long
+      responses:
+        "204":
+          description: Password reset. All active sessions for the account revoked.
+        "400":
+          $ref: "#/components/responses/BadRequest"
+        "401":
+          $ref: "#/components/responses/Unauthorized"
+        "403":
+          $ref: "#/components/responses/Forbidden"
+        "404":
+          $ref: "#/components/responses/NotFound"
+
   /v1/policy/rules:
     get:
       summary: List policy rules (admin)
@@ -1169,6 +1303,16 @@ paths:
                   example: 50
                 rule:
                   $ref: "#/components/schemas/RuleBody"
+                not_before:
+                  type: string
+                  format: date-time
+                  description: Earliest activation time (RFC3339, optional).
+                  example: "2026-04-01T00:00:00Z"
+                expires_at:
+                  type: string
+                  format: date-time
+                  description: Expiry time (RFC3339, optional).
+                  example: "2026-06-01T00:00:00Z"
       responses:
         "201":
           description: Rule created.
@@ -1239,6 +1383,22 @@ paths:
                   example: false
                 rule:
                   $ref: "#/components/schemas/RuleBody"
+                not_before:
+                  type: string
+                  format: date-time
+                  description: Set earliest activation time (RFC3339).
+                  example: "2026-04-01T00:00:00Z"
+                expires_at:
+                  type: string
+                  format: date-time
+                  description: Set expiry time (RFC3339).
+                  example: "2026-06-01T00:00:00Z"
+                clear_not_before:
+                  type: boolean
+                  description: Set to true to remove not_before constraint.
+                clear_expires_at:
+                  type: boolean
+                  description: Set to true to remove expires_at constraint.
       responses:
         "200":
           description: Updated rule.