chore: remove legacy bazel strategy and orphaned BUILD files

- Remove bazel/build/hybrid strategy support from wasm_toolchain.bzl
- Simplify to download-only strategy (matching extensions.bzl cleanup)
- Delete orphaned BUILD.wasm_tools_bazel and BUILD.wizer_bazel files
- Add these files to .gitignore to prevent regeneration
- Remove _setup_bazel_native_tools function (dead code)
- Update all strategy references and error messages

This completes the dependency management consolidation by removing
unreachable code paths and simplifying the toolchain to use only
prebuilt binary downloads from GitHub releases.

Author: avrabe

.gitignore

@@ -80,3 +80,6 @@ coverage/
 perf.data
 flamegraph.svg
 __pycache__/
+
+# Legacy bazel strategy BUILD files (removed in dependency management cleanup)
+toolchains/BUILD.*_bazel

toolchains/wasm_toolchain.bzl

@@ -140,21 +140,14 @@ def _wasm_toolchain_repository_impl(repository_ctx):
     for warning in compatibility_warnings:
         print("Warning: {}".format(warning))
 
-    # All strategies now use modernized approach with git_repository rules
-    # This eliminates ctx.execute() calls for git clone and cargo build operations
+    # Use download strategy for fast, hermetic builds with prebuilt binaries
     if strategy == "download":
-        _setup_downloaded_tools(repository_ctx)  # Use simple method for stability
-    elif strategy == "build":
-        _setup_built_tools_enhanced(repository_ctx)  # Modernized: uses git_repository
-    elif strategy == "bazel":
-        _setup_bazel_native_tools(repository_ctx)
-    elif strategy == "hybrid":
-        _setup_hybrid_tools_enhanced(repository_ctx)  # Modernized: most robust approach
+        _setup_downloaded_tools(repository_ctx)
     else:
         fail(format_diagnostic_error(
             "E001",
             "Unknown strategy: {}".format(strategy),
-            "Must be 'download', 'build', 'bazel', or 'hybrid'",
+            "Must be 'download' (other strategies removed in dependency management cleanup)",
         ))
 
     # Create BUILD files for all strategies
@@ -563,79 +556,20 @@ exit 1
 """, executable = True)
 
 def _download_wasmsign2(repository_ctx):
-    """Setup wasmsign2 placeholder - use bazel strategy for full functionality"""
+    """Setup wasmsign2 placeholder - not available in prebuilt downloads"""
 
     print("Setting up wasmsign2 placeholder for download strategy")
 
-    # Create a stub that explains the limitation and recommends the bazel strategy
+    # Create a stub explaining wasmsign2 is not included in prebuilt downloads
     repository_ctx.file("wasmsign2", """#!/bin/bash
-# wasmsign2 stub for download strategy
-# The download strategy cannot build Rust binaries from source
+# wasmsign2 is not included in prebuilt binary downloads
 echo "wasmsign2: Not available in download strategy" >&2
-echo "For signing functionality, use strategy = 'bazel' in your MODULE.bazel:" >&2
-echo "  wasm_toolchain.register(strategy = 'bazel')" >&2
-echo "This enables Bazel-native rust_binary builds with full signing support." >&2
+echo "WebAssembly component signing requires building wasmsign2 from source" >&2
+echo "For signing functionality, use @wasmsign2_src from git_repository" >&2
 exit 1
 """, executable = True)
 
-    print("Created wasmsign2 stub - use bazel strategy for full signing functionality")
-
-def _setup_bazel_native_tools(repository_ctx):
-    """Setup tools using Bazel-native rust_binary builds instead of cargo"""
-
-    print("Setting up Bazel-native toolchain using rust_binary rules")
-
-    # For Bazel-native strategy, we don't create any local binaries at all.
-    # Instead, we copy the BUILD files that use rust_binary rules and git_repository sources.
-    # This completely bypasses cargo and uses only Bazel + rules_rust.
-
-    # Copy the wasm-tools BUILD file that uses rust_binary
-    repository_ctx.template(
-        "BUILD.wasm_tools",
-        Label("//toolchains:BUILD.wasm_tools_bazel"),
-    )
-
-    # Copy the wizer BUILD file that uses rust_binary
-    repository_ctx.template(
-        "BUILD.wizer",
-        Label("//toolchains:BUILD.wizer_bazel"),
-    )
-
-    # Create placeholder binaries for tools not yet implemented with rust_binary
-    # These will be updated as we add more Bazel-native builds
-
-    # Create placeholder wac (will be updated to rust_binary later)
-    repository_ctx.file("wac", """#!/bin/bash
-echo "wac: Bazel-native rust_binary not yet implemented"
-echo "Using placeholder - switch to 'download' strategy in MODULE.bazel for full functionality"
-echo "To use wac, switch to 'download' strategy in MODULE.bazel"
-exit 1
-""", executable = True)
-
-    # Create placeholder wit-bindgen (will be updated to rust_binary later)
-    repository_ctx.file("wit-bindgen", """#!/bin/bash
-echo "wit-bindgen: Bazel-native rust_binary not yet implemented"
-echo "Using download strategy fallback"
-# For now, fail gracefully and suggest alternative
-echo "To use wit-bindgen, switch to 'download' strategy in MODULE.bazel"
-exit 1
-""", executable = True)
-
-    # Create placeholder wrpc (complex build, keep as placeholder)
-    repository_ctx.file("wrpc", """#!/bin/bash
-echo "wrpc: placeholder - complex dependencies"
-echo "Use system wrpc or download strategy"
-exit 1
-""", executable = True)
-
-    # Create placeholder wasmsign2 (not critical for core functionality)
-    repository_ctx.file("wasmsign2", """#!/bin/bash
-echo "wasmsign2: not critical for WebAssembly component compilation"
-echo "Basic functionality available without signing"
-exit 0
-""", executable = True)
-
-    print("✅ Bazel-native strategy configured - using rust_binary rules for core tools")
+    print("Created wasmsign2 stub - not included in prebuilt downloads")
 
 def _get_platform_suffix(platform):
     """Get platform suffix for download URLs"""
@@ -702,70 +636,6 @@ wasm_tools_toolchain(
     wasmsign2 = ":wasmsign2_binary",
 )
 
-# Toolchain registration
-toolchain(
-    name = "wasm_tools_toolchain",
-    toolchain = ":wasm_tools_impl",
-    toolchain_type = "@rules_wasm_component//toolchains:wasm_tools_toolchain_type",
-    exec_compatible_with = [],
-    target_compatible_with = [],
-)
-"""
-    elif strategy == "bazel":
-        # For Bazel-native strategy, reference rust_binary builds from git repositories
-        build_content = """
-load("@rules_wasm_component//toolchains:wasm_toolchain.bzl", "wasm_tools_toolchain")
-
-package(default_visibility = ["//visibility:public"])
-
-# File targets for executables - use Bazel-native rust_binary builds
-alias(
-    name = "wasm_tools_binary",
-    actual = "@wasm_tools_src//:wasm_tools_bazel",
-    visibility = ["//visibility:public"],
-)
-
-alias(
-    name = "wizer_binary",
-    actual = "@wizer_src//:wizer_bazel",
-    visibility = ["//visibility:public"],
-)
-
-# Remaining tools use local fallback files until rust_binary implementations added
-filegroup(
-    name = "wac_binary",
-    srcs = ["wac"],
-    visibility = ["//visibility:public"],
-)
-
-filegroup(
-    name = "wit_bindgen_binary",
-    srcs = ["wit-bindgen"],
-    visibility = ["//visibility:public"],
-)
-
-filegroup(
-    name = "wrpc_binary",
-    srcs = ["wrpc"],
-    visibility = ["//visibility:public"],
-)
-
-alias(
-    name = "wasmsign2_binary",
-    actual = "@wasmsign2_src//:wasmsign2_bazel",
-    visibility = ["//visibility:public"],
-)
-
-# Toolchain implementation
-wasm_tools_toolchain(
-    name = "wasm_tools_impl",
-    wasm_tools = ":wasm_tools_binary",
-    wac = ":wac_binary",
-    wit_bindgen = ":wit_bindgen_binary",
-    wrpc = ":wrpc_binary",
-    wasmsign2 = ":wasmsign2_binary",
-)
-
 # Toolchain registration
 toolchain(
     name = "wasm_tools_toolchain",
@@ -776,7 +646,7 @@ toolchain(
 )
 """
     else:
-        # For other strategies (download, system, hybrid), use local files
+        # For download strategy, use local downloaded files
         build_content = """
 load("@rules_wasm_component//toolchains:wasm_toolchain.bzl", "wasm_tools_toolchain")
 
@@ -845,9 +715,9 @@ wasm_toolchain_repository = repository_rule(
     implementation = _wasm_toolchain_repository_impl,
     attrs = {
         "strategy": attr.string(
-            doc = "Tool acquisition strategy: 'download', 'build', 'bazel', or 'hybrid'. All strategies now modernized to eliminate ctx.execute() calls.",
-            default = "hybrid",  # Hybrid is most robust with git_repository approach
-            values = ["download", "build", "bazel", "hybrid"],
+            doc = "Tool acquisition strategy: 'download' only (other strategies removed in dependency management cleanup)",
+            default = "download",
+            values = ["download"],
         ),
         "version": attr.string(
             doc = "Version to use (for download/build strategies)",