LCFS - Implement last updated field in fuel code feature (still editing)

**Title:**

**Description:**

**Wireframe:**

**Purpose and benefit to user:**

**Acceptance Criteria:**

- [ ] Given I am a , When I am , then
- [ ] Given I am a , When I am , then

**Development Checklist:**
- [ ] A
- [ ] B
- [ ] C

**Notes:**
| placeholder column for the date the code was last updated (saved, edited, created, approved, etc.);

No files, tests, or entry points are named, and the issue is still an unfilled template. First clarify the fuel-code scope, wireframe, acceptance criteria, and meaning of “last updated”; done should be defined by concrete completed criteria and a named validation path.

Written by the indexing model from the issue text.