chore: initialize repository with project rules, docs, and phase-1 ADRs

Set up the foundation for the adastra-portal project:

- CLAUDE.md captures durable project rules (quality bar, security/perf/a11y
  as first-class, language, commit conventions, ADR proactivity).
- docs/ and decisions/ scaffolding with maintained indexes (docs/README.md
  and decisions/README.md), MADR 4.0.0 template, and tag vocabulary.
- Phase-1 ADRs (0001-0006) lock structural choices: ADR usage, Nx monorepo
  with the apps preset, naming convention (adastra-portal / portal-shell /
  portal-bff), Angular CSR/zoneless/Signals/Vitest, NestJS over Express,
  PostgreSQL with Prisma.
- docs/setup/ guides translated to English.
- .gitignore covers Node/Nx artifacts and the personal notes/ scratchpad.

The Nx workspace itself is not yet bootstrapped; that step is gated on a
revised setup guide aligned with the ADRs.

docs/setup/01-wsl-terminal-setup.md

@@ -0,0 +1,134 @@
+# 🖥️ Modern WSL terminal (Zsh + Powerlevel10k)
+
+## Goal
+
+A terminal that is:
+
+* readable
+* fast
+* equipped with intelligent autocomplete
+* suited for modern development
+
+---
+
+## 1) Install Zsh
+
+```bash
+sudo apt update
+sudo apt install -y zsh
+```
+
+Set it as the default shell:
+
+```bash
+chsh -s $(which zsh)
+```
+
+Under WSL, add the following to `~/.bashrc`:
+
+```bash
+if command -v zsh >/dev/null 2>&1; then
+  exec zsh
+fi
+```
+
+---
+
+## 2) Install Oh My Zsh
+
+```bash
+sh -c "$(curl -fsSL https://raw.githubusercontent.com/ohmyzsh/ohmyzsh/master/tools/install.sh)"
+```
+
+---
+
+## 3) Install Powerlevel10k
+
+```bash
+git clone --depth=1 https://github.com/romkatv/powerlevel10k.git \
+  ${ZSH_CUSTOM:-~/.oh-my-zsh/custom}/themes/powerlevel10k
+```
+
+In `~/.zshrc`:
+
+```bash
+ZSH_THEME="powerlevel10k/powerlevel10k"
+```
+
+Then:
+
+```bash
+source ~/.zshrc
+p10k configure
+```
+
+---
+
+## 4) Install a Nerd Font (on Windows)
+
+Install a Nerd Font on Windows (MesloLGS NF recommended).
+
+Configure it in Windows Terminal:
+
+* Settings → Debian profile
+* Font → MesloLGS NF
+
+---
+
+## 5) Useful plugins
+
+```bash
+plugins=(
+  git
+  fzf
+  zsh-autosuggestions
+  zsh-syntax-highlighting
+)
+```
+
+Install them:
+
+```bash
+git clone https://github.com/zsh-users/zsh-autosuggestions \
+  ${ZSH_CUSTOM:-~/.oh-my-zsh/custom}/plugins/zsh-autosuggestions
+
+git clone https://github.com/zsh-users/zsh-syntax-highlighting \
+  ${ZSH_CUSTOM:-~/.oh-my-zsh/custom}/plugins/zsh-syntax-highlighting
+```
+
+---
+
+## 6) Modern CLI tools
+
+```bash
+sudo apt install -y \
+  bat eza fd-find ripgrep fzf zoxide
+```
+
+Recommended aliases:
+
+```bash
+alias ls="eza --icons"
+alias ll="eza -lh --git --icons"
+alias cat="batcat"
+alias grep="rg"
+alias find="fdfind"
+```
+
+---
+
+## 7) FZF
+
+Add to `~/.zshrc`:
+
+```bash
+[ -f ~/.fzf.zsh ] && source ~/.fzf.zsh
+```
+
+---
+
+## Result
+
+* A modern terminal
+* Fast navigation
+* Higher productivity