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).

AGENTS.md

@@ -37,7 +37,9 @@ packages/    @deepseek-ai/dsh-<pkg> workspaces at packages/<group>/<pkg>/
   settings/    user-settings seam + file-backed provider
   credentials/ credential-reference seam + env-over-.env provider
   acp/         automation-only Agent Client Protocol server
-  ui/          JSON-RPC bridge; boot, approval, interaction plugins
+  interaction/ approval/interaction seams, permission, commands, ask-user tool
+  boot/        shared app-bin boot glue
+  scaffold/    project tooling: helper, launcher, initializer, SDK wire protocol + ends
   examples/    demo bundles (agent-spine + CLI/ACP/JSON-RPC bins) leaves load
   support/     dev/test infrastructure
   util/        zero-dependency utilities