Correlate cross-provider AI sessions with pull requests

[iamtoruk]

Summary

• correlate saved AI sessions from any provider with pull requests using explicit GitHub PR references, exact launcher-prompt matches, and unambiguous shared working directories
• retain attribution provenance and refuse timestamp-only, conflicting, or ambiguous multi-PR propagation
• preserve Claude sidechain folding while allowing tools launched from a sidechain to inherit its resolved parent PR
• retain every pull request row and display all real models as chips instead of opaque +N labels
• redesign the Pull requests screen as modern accordion cards with summary metrics and lighter work-breakdown bars

Validation

• TypeScript typecheck passed
• focused attribution regression suite: 94 tests passed
• Electron dashboard suite: 436 tests passed
• CLI and Electron production builds passed
• real saved-session validation recovered 3 Codex review sessions for PR 790 and all 6 Codex review sessions for PR 791
• full root suite: 2,447 passed, with the existing cli-durable-totals parity failure unchanged; root-level jsdom warnings are also pre-existing

Attribution safety

Time overlap is used only to reduce comparison work and can never create a PR association. Exact evidence is required, and ambiguous evidence remains unattributed rather than charging the wrong PR.