fix(ui-agent-preset): use sentence case for PTC mode

apps/web/tests/snapshots/agent-preset-selection/menu.expected.md

@@ -2,6 +2,6 @@
   - menuitem "Standard mode Full coding agent with file editing, shell, file and web search, skills, planning, goals, subagents, and workflows.":
     - text: Standard mode Full coding agent with file editing, shell, file and web search, skills, planning, goals, subagents, and workflows.
     - img
-  - menuitem "PTC Mode All Standard mode capabilities, with tools exposed through the Code Mode SDK so the model can combine multi-step operations in one TypeScript program."
+  - menuitem "PTC mode All Standard mode capabilities, with tools exposed through the Code Mode SDK so the model can combine multi-step operations in one TypeScript program."
   - menuitem "Minimal mode Two-tool coding agent with persistent bash and str_replace_editor."
   - menuitem "Creator mode Built for creating custom agent presets, with all Standard mode capabilities plus runtime inspection, plugin experiments, and preset-authoring guidance."

packages/client/ui-agent-preset/src/client/locales.ts

@@ -37,7 +37,7 @@ export const en: Record<AgentPresetSettingsKey, string> = {
   presetStandardName: 'Standard mode',
   presetStandardDescription:
     'Full coding agent with file editing, shell, file and web search, skills, planning, goals, subagents, and workflows.',
-  presetCodeName: 'PTC Mode',
+  presetCodeName: 'PTC mode',
   presetCodeDescription:
     'All Standard mode capabilities, with tools exposed through the Code Mode SDK so the model can combine multi-step operations in one TypeScript program.',
   presetMinimalName: 'Minimal mode',