refactor(selection): split selectedAgentId into focus vs edit-modal states; improve Edit modal title

Before this commit one piece of state (`selectedAgentId`) did three
jobs: roster highlight, navigation destination, and Edit-modal open
flag. The three jobs had incompatible lifecycles — highlight should
persist across modal close, navigation should land on a screen
without opening a modal, and the modal itself only wants to open on
explicit intent. The conflation was the root cause of the "Edit: CEO
auto-opens on first Team view" bug (commit 41132e2 patched the most
visible symptom by not pre-selecting the lead agent, but the coupling
remained).

Split into two slice fields:

- `selectedAgentId` — which agent is currently highlighted in the
  roster / OrgChart. Survives modal close. Set by: row click, card
  click, navigation from Inbox / Hiring (all of which pass through
  `openAgentEditor` which sets both so the highlight follows the last
  interaction).
- `editingAgentId` — which agent's Edit modal is open, or
  NEW_ENTITY_ID for the "Request new hire" modal. Only set by
  explicit user action; cleared on modal close. Never set by
  navigation or onboarding — the pre-select pathway cannot
  accidentally open a modal again.

Plumbing:

- `selection.ts`: new `editingAgentId` + `setEditingAgentId`, plus
  clear on `clearCompanyScopedSelections`.
- `useCompanyData.ts`: derive `editingAgent` record from the id.
- `useCompanyController.ts`: forward `editingAgent` on the section
  context.
- `OrganizationSections.tsx`: `agents` section modals read
  `editingAgentId` / `editingAgent`. "Request new hire" button uses
  `setEditingAgentId(NEW_ENTITY_ID)`. Single-click handlers go
  through `openAgentEditor(id)` which updates both states.

Also improved Edit modal title (was "Edit: CEO", a machined English
prefix on a Chinese UI with zero context about the role):

- zh: "编辑 {name}（{role}）"
- en: "Edit {name} ({role})"

Renders as "编辑 CEO（首席执行官）" in the screenshot example.

Covers J9 / S2.

src/renderer/state/slices/selection.ts

@@ -6,7 +6,14 @@ export interface SelectionSlice {
   selectedConnectorId: string | null;
   selectedApprovalId: string | null;
   selectedRunId: string | null;
+  /** Highlighted agent (roster row / orgchart card). Navigation target.
+   *  Does NOT control the Edit modal — see editingAgentId. */
   selectedAgentId: string | null;
+  /** Agent whose Edit modal is currently open, or NEW_ENTITY_ID for the
+   *  new-hire request modal. Only set by explicit user action (row click,
+   *  card click, "Request new hire" button); never by navigation or
+   *  onboarding defaults. Cleared on modal close. */
+  editingAgentId: string | null;
   selectedGoalId: string | null;
   selectedProjectId: string | null;
   selectedWorkspaceId: string | null;
@@ -16,6 +23,7 @@ export interface SelectionSlice {
   setSelectedApprovalId: (id: string | null) => void;
   setSelectedRunId: (id: string | null) => void;
   setSelectedAgentId: (id: string | null) => void;
+  setEditingAgentId: (id: string | null) => void;
   setSelectedGoalId: (id: string | null) => void;
   setSelectedProjectId: (id: string | null) => void;
   setSelectedWorkspaceId: (id: string | null) => void;
@@ -34,6 +42,7 @@ export const createSelectionSlice: StateCreator<
   selectedApprovalId: null,
   selectedRunId: null,
   selectedAgentId: null,
+  editingAgentId: null,
   selectedGoalId: null,
   selectedProjectId: null,
   selectedWorkspaceId: null,
@@ -58,6 +67,10 @@ export const createSelectionSlice: StateCreator<
     set((state) => {
       state.selectedAgentId = id;
     }),
+  setEditingAgentId: (id) =>
+    set((state) => {
+      state.editingAgentId = id;
+    }),
   setSelectedGoalId: (id) =>
     set((state) => {
       state.selectedGoalId = id;
@@ -80,6 +93,7 @@ export const createSelectionSlice: StateCreator<
       state.selectedApprovalId = null;
       state.selectedRunId = null;
       state.selectedAgentId = null;
+      state.editingAgentId = null;
       state.selectedGoalId = null;
       state.selectedProjectId = null;
       state.selectedWorkspaceId = null;