Add file browser, tests, and bin entrypoint

bin/fido

@@ -0,0 +1,61 @@
+#!/usr/bin/env bash
+#
+# fido — launcher for the Fido coding assistant.
+#
+# Installed to $FIDO_HOME/bin/fido (default ~/.fido/bin/fido) by install.sh, but
+# this file also works when run straight from a source checkout (bin/fido ->
+# ../src/fido.js).
+#
+# All per-user state is kept under $FIDO_HOME:
+#   $FIDO_HOME/.env                            your API keys / model config
+#   $FIDO_HOME/state/<workspace>/undo.json     the undo log for that workspace
+#   $FIDO_HOME/state/<workspace>/suspends/     /suspend snapshots for it
+#
+# Every workspace you run fido in gets its own state folder, so undo/suspend
+# history never mixes between projects — and never litters the projects
+# themselves (no more .fido-undo.json / .fido-suspends in your repos).
+
+set -euo pipefail
+
+FIDO_HOME="${FIDO_HOME:-$HOME/.fido}"
+
+# ── Load user config ──────────────────────────────────────────────────────────
+# Exported vars win over any .env inside the workspace, because dotenv (used by
+# src/config.js) never overwrites variables already present in the environment.
+if [ -f "$FIDO_HOME/.env" ]; then
+    set -a
+    # shellcheck disable=SC1090
+    . "$FIDO_HOME/.env"
+    set +a
+fi
+
+# ── Resolve the app directory ─────────────────────────────────────────────────
+if [ -f "$FIDO_HOME/app/src/fido.js" ]; then
+    APP_DIR="$FIDO_HOME/app"
+else
+    # Running from a source checkout: this script lives in <root>/bin/.
+    self_dir="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"
+    APP_DIR="$(cd "$self_dir/.." && pwd)"
+fi
+
+# ── Per-workspace state under $FIDO_HOME/state/<slug>/ ────────────────────────
+# The workspace is the first argument (like the app itself: `fido /path/to/proj`),
+# falling back to the current directory.
+workspace="${1:-$PWD}"
+if [ -d "$workspace" ]; then
+    workspace="$(cd "$workspace" && pwd)"
+else
+    workspace="$PWD"
+fi
+
+# Human-readable, filesystem-safe slug + a short hash to guarantee uniqueness.
+slug="$(printf '%s' "$workspace" | sed -e 's,^/,,' -e 's,/,_,g' -e 's,[^A-Za-z0-9._-],-,g')"
+[ -n "$slug" ] || slug="root"
+sum="$(printf '%s' "$workspace" | cksum | cut -d' ' -f1)"
+state_dir="$FIDO_HOME/state/${slug}-${sum}"
+mkdir -p "$state_dir/suspends"
+
+export UNDO_FILE="$state_dir/undo.json"
+export SUSPEND_DIR="$state_dir/suspends"
+
+exec node "$APP_DIR/src/fido.js" "$@"