feat(web): add solitaire_web Bevy WASM build targeting play.html canvas

Adds a new `solitaire_web` crate that compiles the full `solitaire_engine`
to `wasm32-unknown-unknown` and renders to a `<canvas id="bevy-canvas">`
element in `play.html` — the same ECS code path as desktop and Android.

Changes to enable the WASM target:
- .cargo/config.toml: add wasm32-unknown-unknown rustflags for getrandom
- Workspace Cargo.toml: add solitaire_web member
- solitaire_data/Cargo.toml: gate tokio/reqwest/dirs/keyring to non-wasm
- solitaire_data/src: add wasm32 branch to data_dir() (returns None);
  cfg-gate sync_client network types, auth_tokens, matomo_client
- solitaire_engine/Cargo.toml: gate tokio/reqwest/kira/arboard/dirs/zip
  to non-wasm (mio/cpal/arboard don't compile for wasm32-unknown-unknown)
- solitaire_engine/src/lib.rs: cfg-gate module declarations and re-exports
  for analytics, audio, sync, sync_setup, avatar, leaderboard plugins
- solitaire_engine/src/core_game_plugin.rs: cfg-gate plugin registrations
  that require TokioRuntime (audio, sync, analytics, leaderboard, avatar)
- solitaire_engine/src/resources.rs: cfg-gate TokioRuntimeResource
- solitaire_engine/src/game_plugin.rs: cfg-gate std::fs::remove_file (x10)
- solitaire_engine/src/theme/mod.rs: cfg-gate importer module (uses dirs+zip)
- solitaire_engine/src/settings_plugin.rs: cfg-gate theme ZIP import UI
- solitaire_engine/src/assets/sources.rs: cfg-gate FileAssetReader/user_theme_dir
- solitaire_engine/src/auto_complete_plugin.rs: cfg-gate audio system
- solitaire_engine/src/daily_challenge_plugin.rs: cfg-gate server fetch
- solitaire_engine/src/hud_plugin.rs: cfg-gate AvatarResource import
- solitaire_engine/src/profile_plugin.rs: cfg-gate AvatarResource import
- solitaire_server/web/play.html: minimal HTML canvas shell
- solitaire_web/: new crate (Cargo.toml + src/lib.rs)
- build_wasm.sh: add Bevy WASM build step (cargo + wasm-bindgen + wasm-opt)

All tests pass; clippy --workspace -- -D warnings clean; native build
(solitaire_engine, solitaire_app) unaffected.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

build_wasm.sh

@@ -1,18 +1,21 @@
 #!/usr/bin/env bash
-# Rebuild the solitaire_wasm crate and install the output into
-# solitaire_server/web/pkg/ so the server can serve the replay viewer.
+# Rebuild WASM artifacts and install them into solitaire_server/web/pkg/.
+#
+# Two artifacts are produced:
+#   solitaire_wasm.*  — thin replay-viewer + interactive JS API (wasm-pack)
+#   canvas.*          — full Bevy WASM app for play.html (cargo + wasm-bindgen)
 #
 # Prerequisites:
-#   cargo install wasm-pack
+#   cargo install wasm-pack wasm-bindgen-cli
 #   rustup target add wasm32-unknown-unknown
+#   (optional) cargo install wasm-opt   # for smaller canvas_bg.wasm
 #
 # Run from the repo root:
 #   ./build_wasm.sh
 #
-# The generated files (solitaire_wasm.js + solitaire_wasm_bg.wasm) are
-# committed to git so self-hosters who don't touch the WASM crate can
-# skip this step.  Regenerate after any change to solitaire_wasm/ or
-# solitaire_core/.
+# The generated pkg/ files are committed to git so self-hosters who don't
+# touch the WASM crates can skip this step.  Regenerate after any change to
+# solitaire_wasm/, solitaire_web/, solitaire_engine/, or solitaire_core/.
 
 set -euo pipefail
 
@@ -36,5 +39,38 @@ wasm-pack build \
 # Remove them — we manage the output directory ourselves.
 rm -f "$OUT_DIR/package.json" "$OUT_DIR/.gitignore"
 
+# ---------------------------------------------------------------------------
+# Bevy WASM app (solitaire_web → canvas.js + canvas_bg.wasm)
+# ---------------------------------------------------------------------------
+
+if ! command -v wasm-bindgen &> /dev/null; then
+    echo "error: wasm-bindgen not found." >&2
+    echo "  Install with: cargo install wasm-bindgen-cli" >&2
+    echo "  The CLI version must match the wasm-bindgen crate dep." >&2
+    exit 1
+fi
+
+echo "Building solitaire_web (Bevy WASM app)..."
+cargo build --release --target wasm32-unknown-unknown -p solitaire_web
+
+echo "Running wasm-bindgen for solitaire_web..."
+wasm-bindgen \
+    --out-dir "$OUT_DIR" \
+    --out-name canvas \
+    --target web \
+    "$REPO_ROOT/target/wasm32-unknown-unknown/release/solitaire_web.wasm"
+
+# Optional size optimisation — Bevy bundles are large (~5-15 MB uncompressed).
+# wasm-opt passes are skipped silently when the tool is not installed.
+if command -v wasm-opt &> /dev/null; then
+    echo "Running wasm-opt on canvas_bg.wasm..."
+    wasm-opt -Oz \
+        -o "$OUT_DIR/canvas_bg.wasm" \
+        "$OUT_DIR/canvas_bg.wasm"
+else
+    echo "note: wasm-opt not found; skipping size optimisation."
+    echo "  Install with: cargo install wasm-opt  (or via binaryen)"
+fi
+
 echo "Done. Output:"
 ls -lh "$OUT_DIR"