fix(tui): filter installed plugins by current project before merging

The CLI returns all installed plugins globally, including ones from other
projects. Previously, buildInstalledByID included all of them, so
processAvailablePlugin would merge installed data (Enabled, Version,
InstallPath) from other projects, making available plugins incorrectly
appear as "installed, disabled" in the current project.

Add filterRelevantInstalled to exclude installed plugins that don't
belong to the current project before building the ID map. A plugin is
relevant if it's user-scoped, its projectPath matches workingDir, or
it appears in any settings file for the current project.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

Author: bojanrajkovic

internal/tui/CLAUDE.md

@@ -9,7 +9,7 @@ Implements the two-pane plugin manager interface using Bubble Tea's Elm Architec
 ## Contracts
 
 - **Exposes**: `NewModel(client, workingDir) -> *Model`, implements `tea.Model` interface
-- **Guarantees**: Pending operations (install/uninstall/enable/disable/scope-change) tracked until explicit Apply. Filter preserves selection when possible. Only project/local plugins for current workingDir are shown (plus user-scoped plugins).
+- **Guarantees**: Pending operations (install/uninstall/enable/disable/scope-change) tracked until explicit Apply. Filter preserves selection when possible. All installed plugins are shown regardless of which project they were installed from; scope data reflects the current workingDir.
 - **Expects**: Valid `claude.Client` implementation. Terminal with reasonable size (handles resize).
 
 ## Dependencies

internal/tui/model.go

@@ -401,7 +401,8 @@ func (m *Model) loadPlugins() tea.Msg {
 // Only installed plugins relevant to workingDir are included.
 func mergePlugins(list *claude.PluginList, workingDir string) []PluginState {
 	allScopes := claude.GetAllEnabledPlugins(workingDir)
-	installedByID := buildInstalledByID(list.Installed)
+	relevant := filterRelevantInstalled(list.Installed, workingDir, allScopes)
+	installedByID := buildInstalledByID(relevant)
 	seenInstalled := make(map[string]bool)
 	byMarketplace := make(map[string][]PluginState)
 
@@ -412,7 +413,7 @@ func mergePlugins(list *claude.PluginList, workingDir string) []PluginState {
 	}
 
 	// Process installed plugins not in available list
-	for _, p := range list.Installed {
+	for _, p := range relevant {
 		state, ok := processInstalledPlugin(p, allScopes, seenInstalled)
 		if ok {
 			byMarketplace[state.Marketplace] = append(byMarketplace[state.Marketplace], state)
@@ -422,6 +423,26 @@ func mergePlugins(list *claude.PluginList, workingDir string) []PluginState {
 	return sortAndGroupByMarketplace(byMarketplace)
 }
 
+// filterRelevantInstalled returns only installed plugins relevant to the current project.
+// A plugin is relevant if it's user-scoped, installed in the current workingDir,
+// or appears in any settings file for the current project.
+func filterRelevantInstalled(plugins []claude.InstalledPlugin, workingDir string, allScopes claude.ScopeState) []claude.InstalledPlugin {
+	var result []claude.InstalledPlugin
+	for _, p := range plugins {
+		switch {
+		case p.Scope == claude.ScopeUser:
+			result = append(result, p)
+		case p.ProjectPath == workingDir:
+			result = append(result, p)
+		default:
+			if _, inSettings := allScopes[p.ID]; inSettings {
+				result = append(result, p)
+			}
+		}
+	}
+	return result
+}
+
 // buildInstalledByID creates a map of installed plugins by ID.
 func buildInstalledByID(installed []claude.InstalledPlugin) map[string]claude.InstalledPlugin {
 	result := make(map[string]claude.InstalledPlugin)