home: centralize theme and make home-manager feature-aware

- add home/theme.nix as the single Silicon Volt palette and pass it to
  home modules via extraSpecialArgs
- drive foot, hyprland, hyprlock, mako, fzf, starship, rofi and the
  herdr picker from that palette; raw config files use @color@ tokens
  substituted at build time
- pass my = config.my into home-manager; add my.pi.enable, my.flakeDir
- gate home/pi.nix on my.pi.enable (enabled on hades)
- route zshconf/hyprconf aliases and FLAKE_CONFIG through my.flakeDir
- rename the hyprland monitor option volt.monitors -> hypr.monitors
- fix use_auto_tmux command-substitution bug in zsh/init.zsh
- track home/nvim/config/lazy-lock.json for reproducible plugins
- document theming and toggles in the README

home/nvim/config/lazy-lock.json

@@ -0,0 +1,39 @@
+{
+  "LazyVim": { "branch": "main", "commit": "c10948c50b18fae7f256433afdef09e432410480" },
+  "SchemaStore.nvim": { "branch": "main", "commit": "7e3f6dd6ef6da93f74974521c81d8d5bff0443c5" },
+  "blink.cmp": { "branch": "main", "commit": "78336bc89ee5365633bcf754d93df01678b5c08f" },
+  "bufferline.nvim": { "branch": "main", "commit": "655133c3b4c3e5e05ec549b9f8cc2894ac6f51b3" },
+  "catppuccin": { "branch": "main", "commit": "edefef779ab08ce1a4a404713e3012b0d202bd35" },
+  "conform.nvim": { "branch": "master", "commit": "016802de402556da54c36bd7359b441266b01cdd" },
+  "crates.nvim": { "branch": "main", "commit": "694357861ec9ebf12475ddcdd04ea45a0923c32d" },
+  "flash.nvim": { "branch": "main", "commit": "b6346946d10d07998efee029fb0f7a593806d0cd" },
+  "friendly-snippets": { "branch": "main", "commit": "6cd7280adead7f586db6fccbd15d2cac7e2188b9" },
+  "gitsigns.nvim": { "branch": "main", "commit": "5be654f2232c10ddcad19c1607a67b6b4b78fc29" },
+  "grug-far.nvim": { "branch": "main", "commit": "11595bf747edc270bce2069d1020502ad4ae56cf" },
+  "lazy.nvim": { "branch": "main", "commit": "85c7ff3711b730b4030d03144f6db6375044ae82" },
+  "lazydev.nvim": { "branch": "main", "commit": "ff2cbcba459b637ec3fd165a2be59b7bbaeedf0d" },
+  "lualine.nvim": { "branch": "master", "commit": "221ce6b2d999187044529f49da6554a92f740a96" },
+  "mason-lspconfig.nvim": { "branch": "main", "commit": "67029ccdac1ef8941e13b826417bc0ffac24cc86" },
+  "mason.nvim": { "branch": "main", "commit": "2a6940af80375532e5e9e7c1f2fc6319a1b7a69d" },
+  "mini.ai": { "branch": "main", "commit": "25248c6aa002391936a6200f12d1466015987133" },
+  "mini.icons": { "branch": "main", "commit": "98faae31e9be1cc054ae63485e58ceb185efcad0" },
+  "mini.pairs": { "branch": "main", "commit": "b1c5a726921b7a8c9321e9a7a208aa0571de5810" },
+  "noice.nvim": { "branch": "main", "commit": "7bfd942445fb63089b59f97ca487d605e715f155" },
+  "nui.nvim": { "branch": "main", "commit": "a25dd472316d806eb38a5dd667c2e40da5570c75" },
+  "nvim-lint": { "branch": "master", "commit": "9b99aad869102ac01775187abd8d49017b148612" },
+  "nvim-lspconfig": { "branch": "master", "commit": "51dbf5359da86721662c87ca10eb73add973737b" },
+  "nvim-treesitter": { "branch": "main", "commit": "074aa4422bf029908338e855d0c0f71470a971bb" },
+  "nvim-treesitter-textobjects": { "branch": "main", "commit": "898ee307df58f854d11cd7edd06472574d48014e" },
+  "nvim-ts-autotag": { "branch": "main", "commit": "88c1453db4ba7dd24131086fe51fdf74e587d275" },
+  "persistence.nvim": { "branch": "main", "commit": "b20b2a7887bd39c1a356980b45e03250f3dce49c" },
+  "plenary.nvim": { "branch": "master", "commit": "74b06c6c75e4eeb3108ec01852001636d85a932b" },
+  "rustaceanvim": { "branch": "main", "commit": "f659765f93e207b8c44ee4a90eb88bd6e93bf05f" },
+  "snacks.nvim": { "branch": "main", "commit": "882c996cf28183f4d63640de0b4c02ec886d01f2" },
+  "telescope.nvim": { "branch": "master", "commit": "427b576c16792edad01a92b89721d923c19ad60f" },
+  "todo-comments.nvim": { "branch": "main", "commit": "31e3c38ce9b29781e4422fc0322eb0a21f4e8668" },
+  "tokyonight.nvim": { "branch": "main", "commit": "cdc07ac78467a233fd62c493de29a17e0cf2b2b6" },
+  "trouble.nvim": { "branch": "main", "commit": "bd67efe408d4816e25e8491cc5ad4088e708a69a" },
+  "ts-comments.nvim": { "branch": "main", "commit": "a59d6092213447450191122c9346f309161504cb" },
+  "venv-selector.nvim": { "branch": "main", "commit": "cc4bb3975de8835291f9bb45889e96c6b2795fc4" },
+  "which-key.nvim": { "branch": "main", "commit": "3aab2147e74890957785941f0c1ad87d0a44c15a" }
+}