chore: initial project skeleton

Acauã: Network Detection & Threat Hunting, heuristic analysis over a
rolling 7-day window using deterministic math (time series, graph
theory, information theory) instead of opaque ML models. Third
product in the Ciberfauna ecosystem, alongside Guará and Sabiá.

Follows the ecosystem's established conventions: OpenWolf project
memory, bilingual PT-BR/EN docs and UI, Gitea Actions CI/CD on the
same self-hosted runners, Conventional Commits, SemVer, logo and
productName handling, MIT OR Apache-2.0 licensing.

Architecture decision (made with the project owner after a dedicated
consultation, not the original blueprint's suggested stack): Rust
throughout, not Python/FastAPI/React. Most of the statistics (Bowley
skew, MADM, Shannon entropy, PCR, Z-score, novel-edge detection,
pivot chains) reduces to SQL over an embedded DuckDB/Parquet store;
only the spectral analysis and graph centrality need host-language
code, and both have workable Rust crates. Documented in full, including
six corrections to the original blueprint's math (Rayleigh/Schuster
instead of a degenerate Lomb-Scargle over bare timestamps, an explicit
sentinel for Bowley skew's Q3=Q1 case, Jensen-Shannon instead of
unbounded KL, a dedicated long-connection detector, JA4 vs. JA4+
licensing caution, deterministic per-alert evidence), in
docs/architecture.md.

Skeleton only: crates/acaua-core has the four detection pillars,
fusion, storage, zeek log parsing and the updater as typed stubs that
compile and return a clear "skeleton" status rather than real
detection logic — that is separate, future work. crates/acaua-cli has
serve/analyze/doctor/update. apps/gui is a minimal Tauri shell. Also
already includes the one-click desktop self-update mechanism shared
with Guará and Sabiá (AppImage/.deb/Windows installer), even with no
release published yet, for consistency across the ecosystem.

No Gitea repository exists for this project yet; this is a local-only
commit.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01VAyr8d7HuAdUGB6aA5xmDD

scripts/apt-install.sh

@@ -0,0 +1,32 @@
+#!/usr/bin/env bash
+# Installs apt packages in CI without depending on fast mirrors: reuses cached .deb
+# archives when present and retries with per-attempt timeouts if apt stalls or fails.
+#
+# Usage: scripts/apt-install.sh <cache-dir> <package>...
+set -euo pipefail
+[ $# -ge 2 ] || { echo "usage: $0 <cache-dir> <package>..." >&2; exit 2; }
+cache="$1"; shift
+pkgs=("$@")
+mkdir -p "$cache/partial"
+# apt runs as root and leaves files (lock, .deb) unreadable by non-root runner users;
+# restore ownership on exit so cache directories remain accessible.
+trap 'sudo chown -R "$(id -u):$(id -g)" "$cache" 2>/dev/null || true; rm -f "$cache/lock"' EXIT
+opts=(-o "Dir::Cache::archives=$cache" -y)
+
+# 1) With cached .deb files and package index present: install directly without updating apt lists
+if [ -z "$(dpkg --print-foreign-architectures)" ] && ls "$cache"/*.deb >/dev/null 2>&1 && ls /var/lib/apt/lists/*Packages* >/dev/null 2>&1 && timeout 300 sudo apt-get "${opts[@]}" install "${pkgs[@]}"; then
+  echo "installed from cache"
+  exit 0
+fi
+
+# 2) Cache miss (or multiarch / incomplete): update and install, up to 3 attempts with timeout
+for attempt in 1 2 3; do
+  if timeout 240 sudo apt-get update && { [ -z "$(dpkg --print-foreign-architectures)" ] || timeout 600 sudo apt-get "${opts[@]}" upgrade; } && timeout 600 sudo apt-get "${opts[@]}" install "${pkgs[@]}"; then
+    echo "installed (attempt $attempt)"
+    exit 0
+  fi
+  echo "apt failed or timed out (attempt $attempt of 3)" >&2
+  sleep $((attempt * 10))
+done
+echo "failed to install: ${pkgs[*]}" >&2
+exit 1