feat: auto-provision compass via disinto init from disinto.ai

disinto init now silently downloads the compass from
https://disinto.ai/compass.md to ~/.disinto/compass.md, sets
EXEC_COMPASS in .env, and activates the exec agent. No prompts,
no friction — the compass is public philosophy, not a secret.

Once on disk, the factory cannot modify it. Only the executive
can edit ~/.disinto/compass.md directly.

- site/compass.md: compass hosted on disinto.ai (Codeberg Pages)
- bin/disinto: init downloads compass, sets env var, activates exec
- exec-session.sh, exec-briefing.sh: fallback to ~/.disinto/compass.md
- .env.example: updated comment to reflect auto-provisioning

bin/disinto

@@ -1376,6 +1376,27 @@ p.write_text(text)
   touch "${FACTORY_ROOT}/state/.reviewer-active"
   touch "${FACTORY_ROOT}/state/.gardener-active"
 
+  # Provision executive assistant compass (identity lives outside the repo)
+  local compass_dir="${HOME}/.disinto"
+  local compass_path="${compass_dir}/compass.md"
+  if [ ! -f "$compass_path" ]; then
+    mkdir -p "$compass_dir"
+    if curl -sf --max-time 10 "https://disinto.ai/compass.md" -o "$compass_path" 2>/dev/null; then
+      chmod 600 "$compass_path"
+      # Add EXEC_COMPASS to .env if not already present
+      if ! grep -q '^EXEC_COMPASS=' "$env_file" 2>/dev/null; then
+        printf 'EXEC_COMPASS=%s\n' "$compass_path" >> "$env_file"
+      fi
+      touch "${FACTORY_ROOT}/state/.exec-active"
+    fi
+  else
+    # Compass already exists — just ensure exec is active and env is set
+    if ! grep -q '^EXEC_COMPASS=' "$env_file" 2>/dev/null; then
+      printf 'EXEC_COMPASS=%s\n' "$compass_path" >> "$env_file"
+    fi
+    touch "${FACTORY_ROOT}/state/.exec-active"
+  fi
+
   echo ""
   echo "Done. Project ${project_name} is ready."
   echo "  Config:  ${toml_path}"