extract the workspace framework into its own package

Phase 1: the Workspace/Panel system is `src/workspaces/workspaces`, and it no longer
knows Officer exists.

The proof is its test suite. 114 tests mount `WorkspaceView` under a BARE React tree —
no react-query provider, no router, no Officer hook — which is only possible because
the host now supplies everything: a registry mapping `appType` to a component, and a
layout with a way to change it.

Officer is untouched. All 24 `WorkspaceView` sites and 8 `WorkspaceLayout` sites call
exactly what they called before; `Workspace/index.ts` became an adapter that adds back
the three things that are genuinely ours — the app registry, fullscreen persistence in
sessionStorage, and the handshake that stands the nav header down for a fullscreen
panel.

── The shape, and why it is this shape ──

`core/` is the tree and every operation on it: pure, no dependencies, no React. `react/`
is one renderer. That split is phase 2's whole cost saving — a second renderer reuses
`splitPanel`, `movePanel`, `normalizeLayout` and the rest untouched, and what will not
port is the resize INTERACTION rather than the layout engine.

It was already half done: `layout-utils.ts` imported only `./types`, and `WorkspaceView`
already received `{ key, value, setValue, isLoaded }` as a prop and always wrote through
an updater. The real coupling was the registry, fullscreen, and four UI imports.

Also deleted ~175 lines of dead code — `DragOverlay`, `LayoutEditor`, `WorkspaceHeader`
— referenced by nothing.

── Two dependency traps ──

**A second React.** Declaring react/react-dom in the package produced a second copy
under its own node_modules. Two React instances break hooks at runtime and are invisible
until something renders. The package now declares almost nothing while it lives here.

**Two versions of react-resizable-panels.** The root asks ^4.0.15 (4.6.5),
`src/workspaces/components` asks ^2.1.7 (2.1.9), and this code targets 2.x — v4 has no
`PanelGroup`, no `order`, no `ref` on Panel. Inheriting the root resolution produced a
screenful of type errors that read like a broken extraction and were a version
mismatch. Pinned; the duplication itself is worth fixing one day.

── Verified ──

tsgo clean. Package suite 114/114. Full suite 950 pass / 7 fail, unchanged. Frontend
builds, and the running app was screenshotted against the pre-extraction baseline: 9 of
16 byte-identical, the rest live data and the rotating wallpaper. Panel chrome, headers,
splitters and the grid all render as before.

Docs written as part of the work: the package README is the contract, and
WORKSPACES-NOTES.md carries the open items — panel-to-panel channels, the theme
classes the package still assumes, and phase 2.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>

bun.lock

@@ -135,6 +135,7 @@
         "varuint-bitcoin": "^2.0.0",
         "vaul": "^1.1.2",
         "widgets": "workspace:*",
+        "workspaces": "workspace:*",
         "ws": "^8.18.1",
         "zod": "^4.2.1",
       },
@@ -298,6 +299,13 @@
     "src/workspaces/widgets": {
       "name": "widgets",
     },
+    "src/workspaces/workspaces": {
+      "name": "workspaces",
+      "version": "0.1.0",
+      "dependencies": {
+        "react-resizable-panels": "^2.1.7",
+      },
+    },
   },
   "packages": {
     "@alloc/quick-lru": ["@alloc/quick-lru@5.2.0", "", {}, "sha512-UrcABB+4bUrFABwbluTIBErXwvbsU/V7TZWfmbgJfbkwiBuziS9gxdODUyuiecfdGQ85jglMW6juS3+z5TsKLw=="],
@@ -2360,6 +2368,8 @@
 
     "wif": ["wif@5.0.0", "", { "dependencies": { "bs58check": "^4.0.0" } }, "sha512-iFzrC/9ne740qFbNjTZ2FciSRJlHIXoxqk/Y5EnE08QOXu1WjJyCCswwDTYbohAOEnlCtLaAAQBhyaLRFh2hMA=="],
 
+    "workspaces": ["workspaces@workspace:src/workspaces/workspaces"],
+
     "wrap-ansi": ["wrap-ansi@6.2.0", "", { "dependencies": { "ansi-styles": "^4.0.0", "string-width": "^4.1.0", "strip-ansi": "^6.0.0" } }, "sha512-r6lPcBGxZXlIcymEu7InxDMhdW0KDxpLgoFLcguasxCaJ/SOIZwINatK9KY/tf+ZrlywOKU0UDj3ATXUBfxJXA=="],
 
     "wrap-ansi-cjs": ["wrap-ansi@7.0.0", "", { "dependencies": { "ansi-styles": "^4.0.0", "string-width": "^4.1.0", "strip-ansi": "^6.0.0" } }, "sha512-YVGIj2kamLSTxw6NsZjoBxfSwsn0ycdesmc4p+Q21c5zPuZ1pl+NfxVdxPtdHvmNVOQ6XSYG4AUtyt/Fi7D16Q=="],
@@ -2640,6 +2650,8 @@
 
     "wif/bs58check": ["bs58check@4.0.0", "", { "dependencies": { "@noble/hashes": "^1.2.0", "bs58": "^6.0.0" } }, "sha512-FsGDOnFg9aVI9erdriULkd/JjEWONV/lQE5aYziB5PoBsXRind56lh8doIZIc9X4HoxT5x4bLjMWN1/NB8Zp5g=="],
 
+    "workspaces/react-resizable-panels": ["react-resizable-panels@2.1.9", "", { "peerDependencies": { "react": "^16.14.0 || ^17.0.0 || ^18.0.0 || ^19.0.0 || ^19.0.0-rc", "react-dom": "^16.14.0 || ^17.0.0 || ^18.0.0 || ^19.0.0 || ^19.0.0-rc" } }, "sha512-z77+X08YDIrgAes4jl8xhnUu1LNIRp4+E7cv4xHmLOxxUPO/ML7PSrE813b90vj7xvQ1lcf7g2uA9GeMZonjhQ=="],
+
     "wrap-ansi/ansi-styles": ["ansi-styles@4.3.0", "", { "dependencies": { "color-convert": "^2.0.1" } }, "sha512-zbB9rCJAT1rbjiVDb2hqKFHNYLxgtk8NURxZ3IZwD3F6NtxbXZQCnnSi1Lkx+IDohdPlFp222wVALIheZJQSEg=="],
 
     "wrap-ansi-cjs/ansi-styles": ["ansi-styles@4.3.0", "", { "dependencies": { "color-convert": "^2.0.1" } }, "sha512-zbB9rCJAT1rbjiVDb2hqKFHNYLxgtk8NURxZ3IZwD3F6NtxbXZQCnnSi1Lkx+IDohdPlFp222wVALIheZJQSEg=="],