Extract client SDK package (#1052)

* Extract client SDK package

* Polish SDK client identity defaults

* Build client before dependent CI jobs

* Restore daemon client server export

* Extract protocol and client SDK packages

* Fix provider override schema validation

* Fix app test daemon client imports

* Simplify workspace build targets

* Fix CLI test server build bootstrap

* Run SDK package tests in CI

* Fix rebase package split drift

* Restore lockfile registry metadata

* Update SDK config test for prompt default

* Move terminal stream router test to client package

* Fix rebase drift for protocol imports

* Fix SDK agent capability fixture

* Restore legacy server client exports

* Fix server export compatibility test

* Advertise custom mode icon client capability

* Remove server daemon-client exports

* Format rebased mode control import

* Fix rebase drift for protocol imports

Files added by upstream PRs (#893, #1147, #1154) referenced the pre-split
shared/ paths that this branch moves into @getpaseo/protocol. Redirect
those imports to the protocol package so typecheck stays green after the
rebase.

packages/protocol/src/client-capabilities.ts

@@ -0,0 +1,10 @@
+export const CLIENT_CAPS = {
+  reasoningMergeEnum: "reasoning_merge_enum",
+  // COMPAT(customModeIcons): added in v0.1.84. Old clients pin AgentModeIcon to
+  // a closed enum and crash rendering unknown values; daemon downgrades icons
+  // outside the legacy set to "ShieldCheck" when this cap is absent. Drop the
+  // gate when floor >= v0.1.84.
+  customModeIcons: "custom_mode_icons",
+} as const;
+
+export type ClientCapability = (typeof CLIENT_CAPS)[keyof typeof CLIENT_CAPS];