Epic: Differentiate global vs project scope in Settings UI

[hsteude]

Context

The Settings page currently presents all settings (Providers, Git, MCP, Prompts, Instructions, Appearance) as flat tabs without any indication of whether a setting is global (affects all projects) or project-specific (affects only the current project). This leads to confusion about where settings are stored and what they affect.

Current state:

Setting	Actual Scope	User knows?
Providers	Global	No
Git/SSH	Global	No
MCP Servers	Global only	No
Saved Prompts	Browser (unscoped)	No
Instructions	Project	Partially ("Project Instructions" label)
Appearance	Browser	No

Goal

Make the Settings UI clearly communicate the scope of each setting and allow per-project configuration where it makes sense.

Tasks

• Add project indicator and scope badges to Settings page #140 — Add project indicator and scope badges to Settings page
• Add per-project MCP server enable/disable toggles #141 — Add per-project MCP server enable/disable toggles
• Make saved prompts project-scoped via localStorage #142 — Make saved prompts project-scoped via localStorage

Target state:

Setting	Scope	Badge	Notes
Providers	Global	[Global]	Unchanged behavior
Git/SSH	Global	[Global]	Unchanged behavior
MCP Servers	Global + Project	[Global + Project]	Add globally, enable/disable per project
Saved Prompts	Project	[Project]	Scoped per project in localStorage
Instructions	Project	[Project]	Unchanged behavior
Appearance	Browser	No badge	Unchanged behavior

Key architectural finding

The backend SDK already supports per-project MCP overrides via { enabled: boolean } in the Config type's MCP section. The client.config.update() endpoint (project-scoped) vs client.global.config.update() (global) differentiation is already built into the SDK context. The work is primarily UI-level.