feat(web): permission presets and approval answering for the web UI

The web host now composes the sandboxed product path (sandbox-local +
sandbox-policy behind bash-sandbox/fs-sandbox, with user-approval and
permission on top); BootHostOptions.sandbox carries the deployment
defaults (workspace-write + ask).

createApiProxy owns the approval pending registry: a ctx.approval ask
becomes an answerable approval/requested mux frame with a stable rpcId,
replayed verbatim on every mux open until settled; respond routes by the
echoed rpcId, validates the ApprovalResponsePayload audit correlation,
and broadcasts approval/resolved; the ask's abort signal withdraws the
question as cancelled.

session.permissions / session.setPermission project ctx.permission into
a protocol-owned PermissionOption select; idle switches are held
last-write-wins and
flushed into the next prompted turn (the ACP bridge's anchoring
pattern). The shared hasOpenTurn fold moved to dsh-session,
deduplicating the private copies in user-approval, the ACP bridge, and
the proxy.

Client, per the designer draft: a pending approval takes over the
composer (ApprovalPanel replaces the InputBar — amber strip,
justification headline, paired command, one-shot refuse/allow, keyed by
rpcId so a queued second approval remounts live; the resolved frame
restores the composer); the sidebar session row shows an amber
waiting-approval dot that outranks the running ring (manager-tracked
approvalId set, idempotent under mux-open replays, cleared per
connection generation, lit for uninstantiated sessions too); the
permission selector is a composer bottom-row chip over an invisible
native select, with a presentation-only title-case transform
(workspace-write renders as Workspace Write; wire names untouched). Question placeholders stay in the message flow. The
connection fixture mirrors the host behavior for keyless browser
acceptance.

packages/host/runtime/tsconfig.json

@@ -48,16 +48,31 @@
       "path": "../../session-persistence/session-persistence-jsonl"
     },
     {
-      "path": "../../bash/bash-local"
+      "path": "../../bash/bash-sandbox"
     },
     {
       "path": "../../bash/tool-bash"
     },
+    {
+      "path": "../../sandbox/sandbox"
+    },
+    {
+      "path": "../../sandbox/sandbox-local"
+    },
+    {
+      "path": "../../sandbox/sandbox-policy"
+    },
+    {
+      "path": "../../ui/user-approval"
+    },
+    {
+      "path": "../../ui/permission"
+    },
     {
       "path": "../../compact/compact-basic"
     },
     {
-      "path": "../../fs/fs-local"
+      "path": "../../fs/fs-sandbox"
     },
     {
       "path": "../../fs/fs-policy"