Add SSH Agent (gcr-ssh-agent) as an optional service install (#9399)

* Add SSH Agent as an optional service install

Enables gcr-ssh-agent (already shipped via the gnome-keyring dependency)
so passphrase-protected SSH keys work from any context: the agent prompts
graphically on first use, with opt-in passphrase storage in the keyring.
Adds install/remove commands and Install > Service / Remove > Service
menu entries.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01BReZWvvLsDRUaqgjiRzvZ5

* Clear the agent's SSH_AUTH_SOCK when removing the SSH agent service

The socket's ExecStartPost exports SSH_AUTH_SOCK into the user manager with set-environment, which disabling the socket does not undo, so apps launched after removal still pointed at a stopped agent. The environment.d file also has to be deleted before disable reloads the manager, or the generator re-exports it. Only an SSH_AUTH_SOCK pointing at gcr is cleared, so another agent's stays.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

* Move SSH Agent setup to Setup > Security

Turning on an SSH agent is security configuration of the machine rather than installing software, so it sits with SSHD and the other Setup > Security entries. It hides once enabled, as Sudoless Docker does, and Remove > Service > SSH Agent turns it back off.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

---------

Co-authored-by: Claude Fable 5 <noreply@anthropic.com>
Co-authored-by: David Heinemeier Hansson <david@hey.com>

default/omarchy/omarchy-menu.jsonc

@@ -183,6 +183,7 @@
   "setup.security.fingerprint": {"icon":"󰈷","label":"Fingerprint","when":"omarchy-hw-fingerprint","action":"omarchy-launch-floating-terminal-with-presentation omarchy-setup-security-fingerprint"},
   "setup.security.fido2": {"icon":"","label":"Fido2","action":"omarchy-launch-floating-terminal-with-presentation omarchy-setup-security-fido2"},
   "setup.security.sshd": {"icon":"󰣀","label":"SSHD","action":"omarchy-launch-floating-terminal-with-presentation omarchy-setup-security-sshd"},
+  "setup.security.ssh-agent": {"icon":"󰣀","label":"SSH Agent","when":"! systemctl --user -q is-enabled gcr-ssh-agent.socket","action":"omarchy-launch-floating-terminal-with-presentation omarchy-setup-security-ssh-agent"},
   "setup.security.passwordless-sudo": {"icon":"󰟵","label":"Passwordless Sudo","action":"omarchy-launch-floating-terminal-with-presentation omarchy-sudo-passwordless"},
   "setup.security.sudoless-docker": {"icon":"󰡨","label":"Sudoless Docker","when":"omarchy-sudo-docker --configured","action":"omarchy-launch-floating-terminal-with-presentation omarchy-setup-security-sudoless-docker"},
   "setup.config.hyprland": {"icon":"","label":"Hyprland","action":"omarchy-launch-config-editor \"$HOME/.config/hypr/hyprland.lua\""},
@@ -310,6 +311,7 @@
   "remove.browser.zen": {"icon":"","label":"Zen","when":"omarchy-pkg-present zen-browser-bin","action":"omarchy-launch-floating-terminal-with-presentation 'omarchy-remove-browser zen'"},
   "remove.service.dropbox": {"icon":"","label":"Dropbox","when":"omarchy-pkg-present dropbox","action":"omarchy-launch-floating-terminal-with-presentation omarchy-remove-service-dropbox"},
   "remove.service.tailscale": {"icon":"","label":"Tailscale","when":"omarchy-pkg-present tailscale","action":"omarchy-launch-floating-terminal-with-presentation omarchy-remove-service-tailscale"},
+  "remove.service.ssh-agent": {"icon":"󰣀","label":"SSH Agent","when":"systemctl --user -q is-enabled gcr-ssh-agent.socket","action":"omarchy-launch-floating-terminal-with-presentation omarchy-remove-service-ssh-agent"},
   "remove.ai.chatgpt": {"icon":"","iconFont":"omarchy","label":"ChatGPT Desktop","when":"omarchy-pkg-present openai-codex-desktop","action":"omarchy-launch-floating-terminal-with-presentation omarchy-remove-ai-chatgpt"},
   "remove.ai.claude": {"icon":"","iconFont":"omarchy","label":"Claude Desktop","when":"omarchy-pkg-present claude-desktop","action":"omarchy-launch-floating-terminal-with-presentation omarchy-remove-ai-claude"},
   "remove.ai.dictation": {"icon":"","label":"Dictation","when":"omarchy-pkg-present voxtype-bin","action":"omarchy-launch-floating-terminal-with-presentation omarchy-voxtype-remove"},