[Sync] replace the flat layout with the unified stow tree

Supersedes the old flat .config/ layout (last published 2026-06-28) with the
private repo's structure: one shared base plus per-host overlays.

- packages: common/ gui/ lw/ fl/ wm/ plus install.sh and bin/ tooling
  (dotsync, reconcile-hyde.sh)
- new README covering the layout, deploy order and the HyDE dependency
- current HyDE waybar rig (layouts/, cava), pi agent extensions, claude/
  config, tmux, presenterm, aichat roles
- fish: kp (keepassxc-cli + fzf picker, db path from $KP_DB) and
  bind_M_n_history (alt+1..9 recalls the nth history entry)
- drops cruft that should never have been tracked: the duplicate top-level
  .pi/ copy, btop.log, zellij config.kdl.bak, fish_variables
- .pi/agent/auth.json is gitignored; auth.json.example ships instead

Host-specific work sessions and the personal backlog stay in the private
tree. Endpoint locators in the llamacpp/whisper guides are placeholders
($SERVER, <own-domain>) — the guides themselves stay, since they are the
useful part.

common/.config/presenterm/config.yaml

@@ -0,0 +1,106 @@
+---
+# yaml-language-server: $schema=https://raw.githubusercontent.com/mfontanini/presenterm/master/config-file-schema.json
+defaults:
+  # override the terminal font size when in windows or when using sixel.
+  terminal_font_size: 16
+
+  # the theme to use by default in every presentation unless overridden.
+  theme: dark
+
+  # the image protocol to use.
+  image_protocol: kitty-local
+
+typst:
+  # the pixels per inch when rendering latex/typst formulas.
+  ppi: 300
+
+mermaid:
+  # the scale parameter passed to the mermaid CLI (mmdc).
+  scale: 1
+
+options:
+  # whether slides are automatically terminated when a slide title is found.
+  implicit_slide_ends: false
+
+  # the prefix to use for commands.
+  command_prefix: ""
+
+  # show all lists incrementally, by implicitly adding pauses in between elements.
+  incremental_lists: false
+
+  # this option tells presenterm you don't care about extra parameters in
+  # presentation's front matter. This can be useful if you're trying to load a
+  # presentation made for another tool
+  strict_front_matter_parsing: true
+
+  # whether to treat a thematic break as a slide end.
+  end_slide_shorthand: false
+
+snippet:
+  exec:
+    # enable code snippet execution. Use at your own risk!
+    enable: true
+
+  exec_replace:
+    # enable code snippet automatic execution + replacing the snippet with its output. Use at your own risk!
+    enable: true
+
+  render:
+    # the number of threads to use when rendering `+render` code snippets.
+    threads: 2
+
+speaker_notes:
+  # The endpoint to listen for speaker note events.
+  listen_address: "127.0.0.1:59418"
+
+  # The endpoint to publish speaker note events.
+  publish_address: "127.0.0.1:59418"
+
+  # Whether to always publish speaker notes even when `--publish-speaker-notes` is not set.
+  always_publish: false
+
+bindings:
+  # the keys that cause the presentation to move forwards.
+  next: ["l", "j", "<right>", "<page_down>", "<down>", " "]
+
+  # the keys that cause the presentation to move forwards fast.
+  next_fast: ["n"]
+
+  # the keys that cause the presentation to move backwards.
+  previous: ["h", "k", "<left>", "<page_up>", "<up>"]
+
+  # the keys that cause the presentation to move backwards fast
+  previous_fast: ["p"]
+
+  # the key binding to jump to the first slide.
+  first_slide: ["gg"]
+
+  # the key binding to jump to the last slide.
+  last_slide: ["G"]
+
+  # the key binding to jump to a specific slide.
+  go_to_slide: ["<number>G"]
+
+  # the key binding to execute a piece of shell code.
+  execute_code: ["<c-e>"]
+
+  # the key binding to reload the presentation.
+  reload: ["<c-r>"]
+
+  # the key binding to toggle the slide index modal.
+  toggle_slide_index: ["<c-p>"]
+
+  # the key binding to toggle the key bindings modal.
+  toggle_bindings: ["?"]
+
+  # the key binding to close the currently open modal.
+  close_modal: ["<esc>"]
+
+  # the key binding to close the application.
+  exit: ["<c-c>", "q"]
+
+  # the key binding to suspend the application.
+  suspend: ["<c-z>"]
+
+  # the key binding to skip all pauses in the current slide.
+  skip_pauses: ["s"]