feat(coding-agent): add named-only filter toggle to /resume picker

[w-winter]

Originating issue: #862

The /resume picker already supports search, scope toggling, and sort modes, but named sessions can get lost easily sometimes. This adds a Ctrl+N toggle to filter the list down to sessions named via /name, while keeping the existing search/sort behavior intact (name filtering applies even when the query is empty).

Summary of changes:

• add NameFilter (all | named) to filterAndSortSessions() and apply it before query parsing/matching
• add Ctrl+N in the session selector to toggle Name: All ↔ Name: Named, and show current state in the header
• improve empty-state messaging when the named filter is active (including the escape hatch key)
• tests: add name filter coverage (incl. whitespace-only names excluded via trim())
• add configurable app keybinding toggleSessionNamedFilter (default: ctrl+n) via ~/.pi/agent/keybindings.json
• session selector now uses KeybindingsManager for the named-filter toggle and UI hints/empty-state messaging, so users can remap it (e.g. for Emacs/readline ctrl+n = down)

Files:

• packages/coding-agent/README.md
• packages/coding-agent/src/cli/session-picker.ts
• packages/coding-agent/src/core/keybindings.ts
• packages/coding-agent/src/modes/interactive/components/session-selector-search.ts
• packages/coding-agent/src/modes/interactive/components/session-selector.ts
• packages/coding-agent/src/modes/interactive/interactive-mode.ts
• packages/coding-agent/test/session-selector-path-delete.test.ts
• packages/coding-agent/test/session-selector-search.test.ts

Manual testing:

• /resume: Ctrl+N toggles All/Named; header updates; hint shows ctrl+n: named
• /resume: named filter works with empty search query and with an active query
• /resume: empty state mentions Ctrl+N when no named sessions are available in the current scope
• /resume: named filter toggle works; header updates; hint shows the configured keybinding
• keybindings.json: remapping toggleSessionNamedFilter works (e.g. free up ctrl+n for selectDown)

[aos]

Please make this configurable :-) I rebind ctrl+n in session picker for "select down". Here's part of my keybindings:

  "selectUp": ["up", "ctrl+p"],
  "selectDown": ["down", "ctrl+n"],

[aos]

These are just standard Emacs/readline keybindings btw

[w-winter]

Good call. The named-only toggle is now configurable via ~/.pi/agent/keybindings.json:

{
  "toggleSessionNamedFilter": "whatever"
}

@badlogic Do you want a follow-up that makes the other /resume picker shortcuts configurable too (ctrl+r sort, ctrl+p path toggle, ctrl+d delete), or should we those hardcoded?

[badlogic]

Eeks, I merged the rename in /resume PR first. Could you please rebase and fix up the conflicts? Cheers!

[w-winter]

Eeks, I merged the rename in /resume PR first. Could you please rebase and fix up the conflicts? Cheers!

Yeah can do tomorrow. Are you good with Ctrl+N here and that being reconfigurable via keybindings.json?