Title: Validate Integrity of Uploaded Documents detect Prevent Tampering

## 📖 User Story

**As the team lead,**
I want the system to validate the integrity of the uploaded documents,
So that I can ensure they have not been tampered with or altered via photoshop etc
And prevent any fraudulent applications.

### Context:
If possible we want to review the documents to ensure that they have not been tampered with. Using Google AI it is possible to check the validity of the documents

Documents uploaded are:

BC Driver's License
Notice of Assessment
Property Assessment Notice
Speculation and Vacancy Tax Confirmation
Home Owner Grant declaration
ICBC Certificate of Insurance
Home Insurance Summary
Property Tax Notice
Utility Bill
Government or Crown Corporation official notice
Other proof documents (subject to review by registry staff)

### 📏 Business Rules

- [ ] The system must verify that the uploaded documents have not been altered from their original state
- [ ] If the document is altered, flag it as "Document Integrity Check Failed." and change the status to Full Review
- [ ] The system must flag any documents that cannot be verified for integrity as "Unable to Verify Document Integrity" and send them for "Full Review."
- [ ] If the integrity check passes, the system will flag the application as "Document Integrity Verified."
- [ ] Flags must appear in the Automatic and Provisional Approval Logic page https://www.figma.com/design/R9GF5wvwq2TrnbnsbhPfvV/STR-Application-Tickets?node-id=4871-7178&t=WHxOpgEGyaQBoRHV-4

### 🎭 Story Scenarios

#### Scenario 1: Uploaded document passes integrity check
**Given** the application is flagged as "Not PR Exempt"
**And** a document is uploaded by the host
**When** the system verifies the document’s hash and metadata (I"m not sure if this is the right approach or not
**Then** the system flags the document as "Document Integrity Verified."

#### Scenario 2: Uploaded document fails integrity check due to tampering
**Given** the application is flagged as "Not PR Exempt"
**And** a document is uploaded by the host
**When** the system detects that the document has been tampered with
**Then** the system flags the document as "Document Integrity Check Failed"
**And** sends the application for "Full Review."

#### Scenario 3: System unable to verify document integrity
**Given** the application is flagged as "Not PR Exempt"
**And** a document is uploaded by the host
**When** the system is unable to verify the document's integrity (e.g., unsupported file format or corrupted file)
**Then** the system flags the document as "Unable to Verify Document Integrity"
**And** sends the application for "Full Review."

#### Scenario 4: Multiple documents uploaded with one failing integrity check
**Given** the application is flagged as "Not PR Exempt"
**And** multiple documents are uploaded by the host
**When** the system verifies all documents
**And** one or more documents fail the integrity check
**Then** the system flags those specific documents as "Document Integrity Check Failed"
**And** sends the application for "Full Review."

#### Scenario 5: Partial integrity verification (some documents verified, others not)
**Given** the application is flagged as "Not PR Exempt"
**And** multiple documents are uploaded
**When** some documents pass the integrity check while others cannot be verified
**Then** the system flags the unverifiable documents as "Unable to Verify Document Integrity"
**And** flags the application for "Full Review."

No files, tests, or entry points are identified. Start by resolving whether Google AI and hash or metadata checks can establish integrity for each listed document type, then map the three outcomes and Full Review transitions to the Automatic and Provisional Approval Logic page. Done means all five scenarios and business-rule flags are defined, including mixed-document outcomes.

Written by the indexing model from the issue text.