chore: bootstrap .memory/ project knowledge files

Add initial .memory/ knowledge base for the dotfiles repo:
- knowledge.md: full desktop stack, tool configs, keybindings, conventions
- decisions.md: architectural choices (Hyprland, Fish, Catppuccin Mocha, Neovim, OpenCode)
- research/opencode-architecture.md: detailed OpenCode multi-agent system breakdown

.memory/decisions.md

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+# Dotfiles Decisions
+
+## Desktop Environment: Hyprland + Wayland
+
+- **Decision:** Hyprland as primary compositor, full Wayland stack
+- **Rationale:** Modern Wayland compositor with tiling, animations, and good HiDPI support
+- **Constraints:** XWayland needed for legacy apps; special window rule to suppress maximize events
+- **Input:** Caps Lock remapped to Super (`caps:super`), `alts_toggle` for US/BR layout switching
+
+## Shell: Fish (not Bash/Zsh)
+
+- **Decision:** Fish as primary interactive shell; bash/zsh configs retained for compatibility
+- **Rationale:** Better autocompletion, syntax highlighting, friendly defaults
+- **Plugin manager:** fisher (minimal, text-file-based)
+- **No `oh-my-fish`** — prefer minimal plugin set (just catppuccin theme)
+
+## Theme: Catppuccin Mocha (global)
+
+- **Decision:** Single colorscheme (Catppuccin Mocha) applied uniformly across all tools
+- **Rationale:** Consistent visual identity; official plugins available for Fish, Neovim, Kitty
+- **Other variants installed:** Frappe, Macchiato, Mocha static — available in `fish/themes/` but Mocha is active
+- **No per-tool theming exceptions** — all tools must use Catppuccin Mocha
+
+## Editor: Neovim with lazy.nvim
+
+- **Decision:** Neovim (not VSCode or other) as primary editor
+- **Plugin manager:** lazy.nvim (not packer, not vim-plug) — auto-bootstrapped from init.lua
+- **LSP strategy:** mason.nvim for tooling installation + mason-lspconfig for auto-enable; capabilities injected globally via cmp_nvim_lsp
+- **Format strategy:** conform.nvim with format-on-save (not LSP formatting directly); lsp_fallback=true for unconfigured filetypes
+- **No treesitter-based formatting** — explicit per-filetype formatters in conform
+
+## OpenCode: Custom Multi-Agent Config
+
+- **Decision:** Fully custom multi-agent configuration (not default OpenCode setup)
+- **10 specialized agents** each with tailored instructions, model, temperature, permissions
+- **Memory pattern:** `.memory/` directory tracked in git; agents write to `.memory/*` directly
+- **Permission model:** Full edit for lead/coder/librarian; all others restricted to `.memory/*` writes (instruction-level enforcement, not tool-level)
+- **AGENTS.md exception:** In the opencode subdir, `AGENTS.md` is NOT a symlink (it's the global OpenCode config file, distinct from the per-project `AGENTS.md` pattern)
+- See [OpenCode Architecture](research/opencode-architecture.md) for details
+
+## Waybar CPU Monitor: Ghostty (not Kitty)
+
+- **Observation:** `cpu` module in Waybar opens `ghostty -e htop` on click — Ghostty may be installed as secondary terminal
+- **Impact:** Kitty is the primary terminal (SUPER+Return), but Ghostty is referenced in Waybar config
+
+## Git Credentials: gh CLI
+
+- **Decision:** Use `gh auth git-credential` as credential helper for GitHub + Gist
+- **Rationale:** Centralizes auth through GitHub CLI; no plaintext tokens in git config
+
+## SSH Key Type: Ed25519
+
+- **Decision:** Ed25519 for SSH key (not RSA)
+- **Rationale:** Modern, fast, smaller key size
+
+## No Global `.gitignore` in Dotfiles
+
+- **Observation:** No global gitignore file visible; tracking is managed per-repo
+- **Pattern:** Sensitive SSH private key `.ssh/id_ed25519` is tracked — implies this repo may use filesystem permissions for security