Fix CI: pnpm PATH, Obsidian arch matcher, Arch pkg names, Fedora lazygit COPR

- post.go: export PNPM_HOME+PATH before pnpm add -g so global bins
  install correctly in the non-interactive shell. Applied to
  installNpmPackage and installPlaywright (incl. browser install).
- system.go: treat token-less Obsidian AppImage as x86_64 (upstream
  publishes "Obsidian-X.Y.Z.AppImage" with no arch suffix).
- pkgmgr.go: docker-ce-rootless-extras and vagrant are AUR-only on
  Arch → skipOverride; pipx → python-pipx on pacman.
- repos.go: new setupLazygitCoprRepo enables copr.fedorainfracloud.org/
  dejan/lazygit on Fedora; wired into repoGroups so lazygit installs.
- Tests: PNPM_HOME export (Linux+macOS), token-less Obsidian asset,
  pacman pkg overrides, COPR repo setup, updated repoGroups count.

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

post.go

@@ -478,6 +478,13 @@ func installAgy() {
 	}
 }
 
+func pnpmEnvPrefix() string {
+	if isMacOS {
+		return `export PNPM_HOME="$HOME/Library/pnpm" && export PATH="$PNPM_HOME:$PATH" && `
+	}
+	return `export PNPM_HOME="${XDG_DATA_HOME:-$HOME/.local/share}/pnpm" && export PATH="$PNPM_HOME:$PATH" && `
+}
+
 func installNpmPackage(pkgName string) {
 	home, _ := os.UserHomeDir()
 	if _, err := osStat(filepath.Join(home, ".nvm")); err != nil {
@@ -486,7 +493,8 @@ func installNpmPackage(pkgName string) {
 	}
 	ensureNodeLTS()
 	fmt.Printf("  Installing %s via pnpm ...\n", pkgName)
-	if !runShell(fmt.Sprintf(`bash -c "source ~/.nvm/nvm.sh && pnpm add -g %s"`, pkgName), CmdOpts{}).OK() {
+	cmd := fmt.Sprintf(`bash -c "%ssource ~/.nvm/nvm.sh && pnpm add -g %s"`, pnpmEnvPrefix(), pkgName)
+	if !runShell(cmd, CmdOpts{}).OK() {
 		errLog(fmt.Sprintf("%s installation failed", pkgName))
 	}
 }
@@ -499,7 +507,8 @@ func installPlaywright() {
 	}
 	ensureNodeLTS()
 	fmt.Println("  Installing playwright via pnpm ...")
-	if !runShell(`bash -c "source ~/.nvm/nvm.sh && source ~/.bashrc 2>/dev/null; pnpm add -g playwright"`, CmdOpts{}).OK() {
+	addCmd := fmt.Sprintf(`bash -c "%ssource ~/.nvm/nvm.sh && pnpm add -g playwright"`, pnpmEnvPrefix())
+	if !runShell(addCmd, CmdOpts{}).OK() {
 		errLog("playwright installation failed")
 		return
 	}
@@ -510,7 +519,7 @@ func installPlaywright() {
 	} else {
 		fmt.Println("  Installing Playwright browsers ...")
 	}
-	if !runShell(fmt.Sprintf(`bash -c "source ~/.nvm/nvm.sh && source ~/.bashrc 2>/dev/null; %s"`, installCmd), CmdOpts{}).OK() {
+	if !runShell(fmt.Sprintf(`bash -c "%ssource ~/.nvm/nvm.sh && %s"`, pnpmEnvPrefix(), installCmd), CmdOpts{}).OK() {
 		errLog("playwright browser installation failed")
 	}
 }