build-system: add redbear-bare to dispatch + integrate + build-all

The redbear-bare target (added in 48a6f4c20b) was not registered in
the build dispatchers. Running build-redbear.sh redbear-bare
silently exited with 'ERROR: Unknown config redbear-bare'.

Fix:
- build-redbear.sh: extend the case statement + usage block + error
  message to include redbear-bare
- integrate-redbear.sh: add config/redbear-bare.toml to the configs
  array so source-tree integration picks up the bare target too
- build-all-isos.sh: include redbear-bare in the targets list

This closes the gap where the bare target existed as a config file
and as a recipe branch (REDBEAR_BARE_INITFS) but was invisible to
the build dispatch layer.

(NO AI attribution)

local/scripts/build-all-isos.sh

@@ -7,7 +7,7 @@ JOBS="${JOBS:-$(nproc)}"
 ALLOW_UPSTREAM="${ALLOW_UPSTREAM:-0}"
 BUILD_LOG_DIR="${PROJECT_ROOT}/build/logs"
 
-targets=(redbear-full redbear-mini redbear-grub)
+targets=(redbear-full redbear-mini redbear-grub redbear-bare)
 
 mkdir -p "$BUILD_LOG_DIR"
 

local/scripts/build-redbear.sh

@@ -260,6 +260,7 @@ Configs:
   redbear-full        Desktop/graphics target (default)
   redbear-mini        Text-only console/recovery target
   redbear-grub        Text-only with GRUB boot manager
+  redbear-bare        Stripped-to-bare-minimum: kernel+7-initfs-daemons+zsh login
 
 Environment:
   REDBEAR_RELEASE     If set, builds from immutable release archives.
@@ -301,11 +302,11 @@ fi
 [ ${#POSITIONAL[@]} -eq 1 ] && CONFIG="${POSITIONAL[0]}"
 
 case "$CONFIG" in
-    redbear-full|redbear-mini|redbear-grub)
+    redbear-full|redbear-mini|redbear-grub|redbear-bare)
         ;;
     *)
         echo "ERROR: Unknown config '$CONFIG'" >&2
-        echo "Supported: redbear-full, redbear-mini, redbear-grub" >&2
+        echo "Supported: redbear-full, redbear-mini, redbear-grub, redbear-bare" >&2
         exit 1
         ;;
 esac

local/scripts/integrate-redbear.sh

@@ -202,6 +202,7 @@ declare -a redbear_configs=(
     "config/redbear-mini.toml"
     "config/redbear-full.toml"
     "config/redbear-grub.toml"
+    "config/redbear-bare.toml"
 )
 declare -a found_configs=()