feat(data): Data screen context menus for exhibit, node, ledger and staged kinds#1471

Closes #1151

Summary

The Data screen's rows get their context menus through the shared registry (#701): exhibit (Open in viewer, Copy SHA-256, Copy relative path, Verify), node (Show only this, Expand below, Collapse below, Verify), ledger (Show target, Copy entry hash, Copy previous hash) and staged (Commit, Discard with confirmation, Copy SHA-256 labelled not anchored), exactly the X38 items and nothing else. Every item has an inline or keyboard route on the screen: Enter or a double-click opens a row, the Properties tab grows copy buttons, the strip and the pane header grow Verify, Shift+click on a twist expands or collapses a subtree, a ledger row click shows its target and its hash cells copy on click, and the Staging group's Upload, Commit and Discard buttons are now wired to the #1148 channels with Discard confirmed through one dialog whichever way it is reached. No item invokes shell:showItemInFolder; #1194 stays open. #1468, #1469 and #1470 are on main, so the verification block scores this PR's own diff.

Changes

• src/renderer/components/contextmenu/entityMenu.ts: the four kinds, their entries and headers
• src/renderer/components/data/useDataContextMenu.ts: targets built over the screen's own callbacks
• src/renderer/components/data/DiscardStagedDialog.tsx, copy.ts: the confirm step and the clipboard helper
• src/renderer/lib/api/staging.ts: upload, commit and discard mutations with their invalidations
• src/renderer/components/data/DataTree.tsx, ArtifactTable.tsx, ManifestLedger.tsx, PropertiesTab.tsx, ArtifactTabs.tsx, ledgerModel.ts: menu wrappers and the inline routes
• src/renderer/components/dashboard/cases/DataExplorer.tsx: wiring, live staging actions, Open in viewer through the Captures route
• tests/components/DataExplorerContextMenu.test.tsx (new), tests/renderer/api/staging.test.ts (new), tests/components/entityMenu.test.tsx, screen test updates
• docs/agents/architecture.md: component list

Evidence-affecting

Yes

Evidence impact

• Evidentiary result or interpretation that could change: Commit writes to the chain and is now reachable from the screen; Discard deletes pooled bytes that nothing records, which is why it confirms. Copy SHA-256 writes the stored digest unchanged, and the pooled row's copy is labelled not anchored so a pasted hash cannot read as evidence. An item is enabled only when its inline route is: Copy relative path needs a recorded path, Copy entry hash needs a readable entry, Copy previous hash needs a readable non-genesis entry (an unreadable line shows no hash and only a readable first entry reads genesis), Show target needs an id the inventory still holds, and a node's Verify covers the rows the node shows this session, so Verify on Integrity Exceptions verifies exactly the exceptions listed and the pane header on a Selector node verifies exactly its hits.
• What verification proves and does not prove after this change: unchanged; Verify from a row, a node or the strip is the same exhibits:verify per Exhibit in sequence, and a verify that throws re-buckets the row as unverified for the session (#1470).
• Backward verification preserved (existing evidence packages still verify): yes; no main-process code changes beyond what #1469 carries.
• Known-answer test added or extended, or why none applies: entityMenu.test.tsx pins the four kinds' items, order and gating (no path, genesis, no target, no viewer) and the absence of any reveal-in-folder route; DataExplorerContextMenu.test.tsx pins each item against the bridge call or state change it accelerates, the unchanged hash and path on the clipboard, that Enter on an inline button in the table or on a ledger hash cell is that button's activation and not a row open or Show target, that an unreadable ledger line shows no hash and copies none, that the pane header's Verify on a Selector node covers exactly the matched rows, that Discard reaches the channel only through the confirm, and that node Verify on Integrity Exceptions covers the session's exceptions and goes off once they clear.

Verification

pnpm preflight at 8891fe797a1950447c93cf02f1ee8166180a6bf5 on Node v20.20.2; diff scored against origin/main (merge base 6a1637935). Result: pass.

• pnpm lint - pass (exit 0)
• pnpm lint:boundaries - pass (exit 0)
• pnpm lint:agents-md - pass (exit 0) - CLAUDE.md and AGENTS.md match
• pnpm typecheck - pass (exit 0)
• pnpm build - pass (exit 0)
• pnpm build:extension - skipped - no extension/ changes
• pnpm test:coverage - pass (exit 0) - 4222 passed, 10 skipped (4232), thresholds met
• pnpm coverage:diff - pass (exit 0) - 94.55% of 165 changed lines covered (floor 90%)

Pull request description generated by Claude Code