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).

knip.json

@@ -513,7 +513,7 @@
         "tests/**/*.ts"
       ]
     },
-    "packages/ui/jsonrpc": {
+    "packages/scaffold/server": {
       "entry": [
         "tests/**/*.spec.ts",
         "tests/**/*.e2e.ts"
@@ -523,7 +523,7 @@
         "tests/**/*.ts"
       ]
     },
-    "packages/ui/commands": {
+    "packages/interaction/commands": {
       "entry": [
         "tests/**/*.spec.ts"
       ],
@@ -537,7 +537,7 @@
         "src/**/*.ts"
       ]
     },
-    "packages/sdk/create-sdk": {
+    "packages/scaffold/create-sdk": {
       "entry": [
         "src/bin.ts",
         "tests/**/*.spec.ts",
@@ -549,7 +549,7 @@
         "tests/**/*.ts"
       ]
     },
-    "packages/sdk/scripts": {
+    "packages/scaffold/scripts": {
       "entry": [
         "src/bin.ts",
         "tests/**/*.spec.ts",