restructure: move web app into sources/

All served files (index.html, core/, pages/, components/, vendor/,
config.json, icons.json, favicon.svg) are now under sources/.
build.sh and components.yml stay at the repo root.
build.sh updated: WEB_DIR → sources/, MANIFEST stays at SCRIPT_DIR.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
Signed-off-by: GnomeZworc <nicolas.boufidjeline@g3e.fr>

build.sh

@@ -14,8 +14,9 @@
 
 set -euo pipefail
 
-WEB_DIR="$(cd "$(dirname "$0")" && pwd)"
-MANIFEST="${WEB_DIR}/components.yml"
+SCRIPT_DIR="$(cd "$(dirname "$0")" && pwd)"
+WEB_DIR="${SCRIPT_DIR}/sources"
+MANIFEST="${SCRIPT_DIR}/components.yml"
 COMPONENTS_DIR="${WEB_DIR}/components"
 OUTPUT="${WEB_DIR}/components.json"
 LOCKFILE="${WEB_DIR}/components.lock.json"