Views missing GET handlers: merge_select, bulk_actions, image_upload (US-DM)

[andrewyager]

Description

Several views only handle POST requests but have no GET handler, making them inaccessible as standalone pages. Users navigating to these URLs directly get unexpected responses.

Spec Sections: S10B (US-DM-008, US-DM-011, US-DM-032)
Severity: LOW

Gaps

1. asset_merge_select — GET redirects to /assets/ (302) instead of rendering a merge selection form
2. bulk_actions — GET has no handler (US-DM-032)
3. image_upload — GET has no handler for rendering an upload form (US-DM-008)

Xfail Test Coverage (3 tests)

File	Test	Reason
test_dept_manager.py	TestUS_DM_011::test_merge_select_page_loads	asset_merge_select view has no GET handler
test_dept_manager.py	TestUS_DM_032::test_bulk_print_accessible	bulk_actions view has no GET handler
test_dept_manager.py	TestUS_DM_008::test_image_upload_accessible_for_own_dept	image_upload view has no GET handler

Branch: feature/test-reorganisation-and-functional-suite (PR #37)