[hsusul]

Why

The archive UI restored in #18 is an older three-pane shell. This PR replaces it with a new design built around search. It keeps every capability and uses only what src/ipc.ts exposes.

What changed

• A query line spans the top bar. Its scope chip picks what to browse: all sessions, one repository, or one folder. The same chip narrows a search to the repository. Filters tint in place as you type, and an empty line shows the filter reference.
• A virtualized list sits beside a reader. The reader has Conversation, Files, and Git tabs, collapsible tool calls, numbered diffs, and search words highlighted in the transcript. A status bar shows agent counts, messages, and scan progress.
• Navigation state lives in one reducer in src/hooks/workspace.ts. Data hooks drop responses that lost a race to a newer request. In-app dialogs replace window.confirm and window.prompt.

Scope

• Covers the whole archive UI: browse, search, the reader, folders, export, forget, settings, backups, onboarding, palette, and rescan.
• Adds search sort (best match, newest, oldest), which searchPage already supported.
• Leaves out the Memories section. The top bar and reducer have room for a second section when its backend exists.

Tradeoffs

• A three-pane mail layout (rail, list, reader) was rejected. At 900px it leaves the reader about 380px wide, which clips patches.
• A single-column stack (list, then a full-width reader) was rejected. It loses list context while you read.
• Repositories and folders moved from a permanent rail into the scope picker and the palette. Drag-and-drop filing became a "File in folder" control in the reader.

Blast Radius

Only the webview UI changes: src/App.tsx, src/components, src/hooks, and src/styles.css. The IPC contract, main.tsx, and the Tauri shell are untouched. The bundled IBM Plex fonts are the only new dependencies, and the existing font-src 'self' CSP allows them.

Verification

• npm run lint, npm run typecheck, npm test (7 files, 64 tests), and npm run build pass. cargo build -p lore-app builds against the new dist/.
• Behavior tests drive App over a mocked ipc module: filtered and scoped search, empty and failed states, keyboard flow, scan progress, patches, filing, and forgetting. Removing the stale-response guard in useOpenSession makes the out-of-order test fail.
• Checked in Chrome against a local mock and against the p1-2-archive-mock branch merged locally (never pushed). Screenshots cover light, dark, and 900px. The orchestrator has the local paths.