Define read/edit navigation and preserve existing item links #106

Work

Specify read versus edit routes/modes with #73/#82. Inventory task/memory links, copied URLs, creation redirects, browser history, personal/project scopes and showClosed filters. Define authorized edit controls and a dirty-form leave flow. Coordinate ownership with #84/#85.

Acceptance

• Existing links default to read views and continue resolving after route changes.
• Edit, Save, Cancel and Back destinations documented with examples.
• Creation remains a form; no duplicated renderer/editor implementation.

Dependency

First step under #103; route decisions must agree with active #73.