feat: align Herdr keyboard navigation with the desktop

Add direct Ctrl+Alt pane, workspace, picker and agent navigation while retaining prefix shortcuts. Manage the existing theme and sidebar preferences with the keymap in Home Manager. Record Herdr as the chosen manager and defer agent evaluation.

Formatting, rendered TOML parsing, flake evaluation, Zenith system build and whitespace checks passed. User activation and interactive keyboard acceptance remain; no live sessions were changed.

docs/constellation-work.md

@@ -83,10 +83,10 @@ coherent commit before starting unrelated work.
   in ordinary normal/visual buffers, and Blink Escape cancellation. The existing
   `tests/neovim-ergonomics.lua` is retained; earlier smoke-check evidence is in the
   archived plan, with interactive preview restoration/visual behavior unproven.
-- **Agents:** agent-deck, Herdr and tmux coexist; no replacement has been chosen.
+- **Agents:** Herdr is selected; agent-deck and tmux remain installed alongside it.
   Codex has agent-deck notifications and hooks enabled. Shared Context7/NixOS skills
   live under `.agents/skills`; a Nix-managed marketplace exposes Ponytail.
-  Zellij is also declared on workstations. None of this selects a session workflow.
+  Zellij is also declared on workstations. Detailed project workflow remains open.
 - **SharePoint:** Zenith declares an hourly service syncing `company-sharepoint:`
   into `~/.local/share/yookr-reference/sharepoint/Algemeen` and
   `company-sharepoint-projecten:` into `Projecten`. Each invocation has
@@ -122,10 +122,10 @@ The focus is the broader environment, not further API/database polish. Candidate
 areas remain places/ownership, navigation/interaction, human/agent collaboration,
 and system operation/maintenance; these are discussion areas, not a work queue.
 
-Current discussion: consistent project/agent work and Niri workspace use. The user
+Current choice: keep Herdr and configure its keys. The user likes its structure,
-values Herdr's spaces and overview of running/waiting agents, but dislikes its
+spaces and overview; keyboard interaction is the issue. Agent evaluation is
-keybindings and mouse orientation. Agent-deck has startup issues (not diagnosed).
+explicitly deferred. Do not resume replacement-tool comparisons or ask for an
-Kitty/Niri, tmux and Zellij are candidates, not selected replacements.
+evaluation task/budget as a prerequisite for this work.
 
 Read-only inspection found existing Niri overview, workspace movement and tabbed
 columns; Kitty has no declared project/session organization. Installed versions:
@@ -145,22 +145,33 @@ worktrees for independent writing efforts, one integration owner. Keep enduring
 repository rules in AGENTS.md, current goals/acceptance in task prompts, and durable
 decisions/current state in existing project docs. No fixed agent team is selected.
 
-Proposed comparison: hold the desktop and model settings fixed; compare solo,
+Herdr configuration is now declared in `modules/capabilities/ai.nix`, including
-solo plus independent review, then bounded parallel delegation on the same starting
+the existing Kanagawa theme, workspace-sorted agent panel and disabled toasts.
-commit and task. Record accepted correctness, unnecessary complexity, human
+Home Manager owns `~/.config/herdr/config.toml` after activation; maintain these
-interventions/rework, total completion time and aggregate usage including workers.
+preferences in Nix. Its configured `.bak` mechanism preserves the previous regular
-Use fresh isolated runs and common acceptance checks; repeat promising variants
+file. Direct Ctrl+Alt bindings supplement the existing Ctrl+B prefix shortcuts:
-before drawing reliability conclusions. Measure desktop navigation separately.
-[Codex subagents](https://learn.chatgpt.com/docs/agent-configuration/subagents)
-and [evaluation guidance](https://developers.openai.com/api/docs/guides/evaluation-best-practices)
-support bounded delegation and task-specific evaluation; the proposed trial is
-not a measured result. No benchmark framework or comparative runs created.
 
-Inputs requested together: typical project/agent count and clients; required
+| Ctrl+Alt + | Action |
-persistence (project switch, terminal close, logout/reboot, remote connection);
+| --- | --- |
-a representative trial task and rough time/spend limit. These determine the first
+| H / J / K / L | Focus pane left / down / up / right |
-concrete trial. No configuration changes, tests, activation or agent runs in this
+| U / I | Next / previous workspace |
-discussion; documentation whitespace checked.
+| O / G | Workspace picker / goto picker |
+| 1–9 | Focus agent |
+| [ / ] | Previous / next tab |
+| Enter | New tab |
+| V / Minus | Split right / down |
+| F | Zoom pane |
+| Q | Detach, leaving the session running |
+
+Inside workspace navigation, U/I moves down/up and H/J/K/L retains pane navigation.
+Niri and Kitty bindings are unchanged. Syntax and action names were checked against
+the installed Herdr 0.9.0 default config and current upstream documentation.
+Interactive delivery through Kitty remains for user acceptance after activation.
+Reload Herdr with its existing Ctrl+B then Shift+R binding after activating Nix.
+Verification: repository formatting, rendered TOML parsing, flake evaluation,
+Zenith no-link system build and whitespace checking passed. No tests, activation
+or live Herdr session changes performed. Next input is the user's activation and
+combined feedback on pane/workspace movement, the pickers and agent jumps.
 
 Mail search remains unresolved. The workbench's custom mail reader, inventory
 pilot, justfile and old README are archived; native Garden/kubectl/K9s now own the

docs/constellation.md

@@ -30,16 +30,16 @@ use a flake to declare its tools without Nix owning the surrounding workspace.
 - Outlook is acceptable as an application, but its interaction and integration
   do not fit as naturally. Accessible mail for tools and agents matters separately
   from choosing a mail reader. Preserve meaning and source context, not just text.
-- Herdr provides useful structure: spaces, running agents and visible attention
+- Herdr is the chosen agent workspace manager: its spaces, running-agent overview
-  states. Its keybindings and mouse-oriented interaction fit poorly. Agent-deck
+  and attention states fit. Adapt its keybindings to the keyboard-driven setup.
-  gave a poor first impression through startup issues; no replacement is selected.
+  Use Ctrl+Alt for direct Herdr actions alongside Super for Niri and Ctrl navigation
-  Explore whether Niri/Kitty or a terminal multiplexer can provide a more composable
+  in Neovim; retain Herdr's prefix bindings. Agent-deck's startup issues and other
-  workflow while retaining that understandable overview.
+  session-manager alternatives are not the current focus.
 - Current friction is a lack of consistent project and agent working practices,
   including Niri workspace use. Tool choice and agent collaboration need to be
   considered together. Alignment, maintainability and human attention matter
-  alongside speed/cost; compare workflows through concrete tasks before adopting
+  alongside speed/cost. Agent-workflow evaluation is deferred; no fixed delegation
-  a fixed delegation pattern.
+  pattern has been selected.
 - Repositories should contain code and documentation needed by that code, not
   become containers for general notes and company material destined for Git remotes.
 - Company work includes repositories, reference material, notes, credentials and

modules/capabilities/ai.nix

@@ -120,6 +120,41 @@ in
         pkgs.ctx7
       ];
 
+      xdg.configFile."herdr/config.toml".text = ''
+        onboarding = false
+
+        [theme]
+        name = "kanagawa"
+        auto_switch = false
+
+        [ui]
+        agent_panel_sort = "spaces"
+
+        [ui.toast]
+        delivery = "off"
+
+        [keys]
+        # Super belongs to Niri; Ctrl navigation belongs to Neovim.
+        focus_pane_left = ["prefix+h", "ctrl+alt+h"]
+        focus_pane_down = ["prefix+j", "ctrl+alt+j"]
+        focus_pane_up = ["prefix+k", "ctrl+alt+k"]
+        focus_pane_right = ["prefix+l", "ctrl+alt+l"]
+        next_workspace = "ctrl+alt+u"
+        previous_workspace = "ctrl+alt+i"
+        navigate_workspace_down = "u"
+        navigate_workspace_up = "i"
+        workspace_picker = ["prefix+w", "ctrl+alt+o"]
+        goto = ["prefix+g", "ctrl+alt+g"]
+        focus_agent = "ctrl+alt+1..9"
+        previous_tab = ["prefix+p", "ctrl+alt+["]
+        next_tab = ["prefix+n", "ctrl+alt+]"]
+        new_tab = ["prefix+c", "ctrl+alt+enter"]
+        split_vertical = ["prefix+v", "ctrl+alt+v"]
+        split_horizontal = ["prefix+minus", "ctrl+alt+minus"]
+        zoom = ["prefix+z", "ctrl+alt+f"]
+        detach = ["prefix+q", "ctrl+alt+q"]
+      '';
+
       home.file.".codex/AGENTS.md".text = ''
         # Environment