feat(research): add project copy workflow

[hubab1]

Summary

• adds an exact-generation tracked-app picker and immutable full-project copy preview
• requires explicit confirmation for new tracks while supporting a validated no-op path for all-already-tracked projects
• preserves copy success separately from an optional exact-scope rankings and popularity refresh
• handles stale projects, removed or reincarnated targets, cancellation, pagination races, redacted errors, and accessible status text
• wires the workflow through KeywordResearchModelFactory and marks background-store revisions only for inserted or converged copies

Verification

• 474 tests passed with zero failures or skips
• focused copy-model and factory integration suites passed
• signed macOS build succeeded
• codesign deep strict verification passed
• project file lint, Swift parse checks, and diff checks passed
• three independent P1/P2 reviews are clear

Stack

• depends on feat(research): add atomic project copy #60
• kept as a draft for manual UI validation before merge