refactor(packages): dissolve ui/ and rename sdk/ to scaffold/

git mv per the regrouping RFC: the five human-collaboration seams and
tui join packages/interaction/, app-boot becomes packages/boot/, and
jsonrpc joins the renamed scaffold/ (formerly sdk/) as its server half
beside client/protocol/create-sdk/helper/scripts/telemetry, whose
folders drop the legacy sdk- prefix. Three new group README triplets
replace the ui/ and sdk/ ones; tsconfig references/paths/globs,
knip keys, vitest globs, gate scripts, catalogs, docs, and the
lockfile follow. Adds the four settled FIXME rename markers
(dsh-sdk-server, dsh-sdk-telemetry, dsh-sdk-helper, dsh-sdk-scripts).

The scaffold folders diverge from their npm names until those renames
land, so tsconfig.base.json maps the three affected names explicitly
beside the group wildcard. Also repairs two pre-existing stale-path
classes the strengthened sweep surfaced: docs/web-styling.md's retired
web-ui host package and type-model spec fixture-literal joins.

app-boot's three Loader-composition specs time out at the default 5s
under full-suite parallel load on this filesystem (pre-existing;
pass isolated with --testTimeout=30000); interaction/scaffold/boot
suites otherwise green (687 passed).

vitest.config.ts

@@ -32,8 +32,8 @@ const windowsUnsupportedPackages = process.platform === 'win32'
       'packages/subprocess/*',
       'packages/pty/pty-local',
       'packages/sandbox/sandbox-local',
-      'packages/sdk/create-sdk',
-      'packages/sdk/helper',
+      'packages/scaffold/create-sdk',
+      'packages/scaffold/helper',
     ]
   : []
 
@@ -83,7 +83,7 @@ const processBoundTests = [
   'packages/subprocess/subprocess-local/tests/spawn.spec.ts',
   'packages/context/time-context/tests/time-context.spec.ts',
   'packages/llm/llm-pi-ai/tests/adapter.spec.ts',
-  'packages/ui/app-boot/tests/app-boot.spec.ts',
+  'packages/boot/app-boot/tests/app-boot.spec.ts',
   'packages/workflow/workflow-workerthread/tests/session.spec.ts',
 ]
 
@@ -222,8 +222,8 @@ export default defineConfig({
         // Projection/command round: executor lifecycle branches and the
         // registry's drive tails need the same maturing lanes. TODO(gui):
         // cover and remove with the client test lane above.
-        'packages/ui/commands/src/index.ts',
-        'packages/ui/commands/src/invariant.ts',
+        'packages/interaction/commands/src/index.ts',
+        'packages/interaction/commands/src/invariant.ts',
         'packages/session/session-projection/src/index.ts',
         ...windowsUnsupportedPackages.map(path => `${path}/src/**/*.ts`),
         ...windowsCoverageExclusions,