Add daemon-level Do Not Disturb / Focus mode

[0xferrous]

wispd should support a daemon-level Do Not Disturb / Focus mode that suppresses popup notifications without dropping notification delivery/state.

Why

This fits the current direction of the project:

• history (Add notification history with configurable persistence #1): suppressed notifications should still be retained
• notification center (notification center with per-app grouped stacks #2): suppressed notifications should still be reviewable later
• wispctl (add wispctl control CLI #3): DND should be scriptable for keybindings, compositor integration, and automation

Desired behavior

When DND/focus mode is enabled, wispd should:

• suppress normal popup notifications
• still accept notifications over org.freedesktop.Notifications
• still retain them in history
• still make them available to the future notification center
• preserve replaces_id behavior for updated notifications

Bypass policy should be defined, for example:

• allow critical urgency through
• optionally allow configured exceptions based on notification metadata such as app_name, desktop-entry, and category

When DND is disabled, suppressed notifications should not be replayed as a burst of old popups by default; they should remain available via history/center.

Possible config shape

[dnd]
enabled = true
allow_critical = true

[[dnd.allow]]
desktop_entry = "org.signal.Signal"

[[dnd.allow]]
app_name = "Calendar"

[[dnd.allow]]
category = "alarm"

Config naming is flexible, but the idea is:

• app_name matches the Notify call field
• desktop_entry maps to the desktop-entry notification hint
• category maps to the category notification hint

Control surface

This should support runtime:

• enable
• disable
• toggle
• status query

This likely belongs in the control path planned in #3, e.g. wispctl dnd on|off|toggle|status.

State model

DND should be a presentation policy, not a delivery failure:

• notifications are still received
• popup suppression is separate from dismissal/removal
• history/center state remains intact

Acceptance criteria

• users can enable/disable DND/focus mode
• normal notifications are suppressed from the live popup stack while active
• suppressed notifications are still received and retained
• replaces_id continues to work correctly during DND
• bypass behavior is clearly defined
• runtime control/query is available, ideally via the future control CLI/API

[shazow]

Could converge on using properties.Get('org.freedesktop.Notifications', 'Inhibited') to detect general DND mode, same property KDE uses.

But having some support for custom focus modes would be a nice v2 feature.