feat(wit): implement Bazel-native external WIT dependency resolution

Add comprehensive support for managing external WebAssembly Interface Type (WIT)
dependencies using Bazel's http_archive and module extension system, eliminating
the need for shell scripts or external package managers like wit-deps.

**Key Features:**
- WASI WIT interfaces available via @wasi_io//:streams and new module extension
- Bazel-native http_archive rules for external WIT packages with SHA256 verification
- Cross-platform, hermetic dependency management following project's Bazel-first principles
- Comprehensive documentation with examples and migration guidance

**Technical Changes:**
- Added wit/wasi_deps.bzl with WASI interface definitions (wasi:[email protected])
- Created wasi_wit module extension in wasm/extensions.bzl for dependency loading
- Updated MODULE.bazel to enable WASI WIT dependencies via extension
- Fixed Go component examples to use correct WIT worlds and dependencies
- Re-enabled //examples/go_component/... targets in CI (removed exclusions)

**Documentation:**
- Created comprehensive External WIT Dependencies guide (/guides/external-wit-dependencies.mdx)
- Added external dependency examples to wit_library rule reference
- Updated toolchain configuration guide with WIT dependencies quick reference
- Provided practical examples for custom, organization-wide, and WASI dependencies

**Fixes:**
- Resolves GitHub issue #17: Go component WIT dependency resolution issues
- Fixes "package 'wasi:[email protected]' not found" errors in wit-bindgen markdown generation
- Enables successful documentation generation for Go components using WASI interfaces

**Testing:**
- Go component examples now build and generate documentation successfully
- All dependencies use proper version matching (0.2.6) between imports and packages
- CI builds include Go component targets without exclusions

Author: avrabe

.github/workflows/ci.yml

@@ -88,7 +88,7 @@ jobs:
           echo "Publishing test components to localhost:5001 registry..."
           bazel run //examples/simple_oci_test:publish_greeting
           bazel run //examples/simple_oci_test:publish_calculator
-          
+
           # Verify components are available
           echo "Verifying registry contents..."
           curl -s http://localhost:5001/v2/_catalog || echo "Registry catalog request failed"
@@ -102,8 +102,6 @@ jobs:
             -//examples/multi_profile/... \
             -//examples/cpp_component/... \
             -//examples/js_component/... \
-            -//examples/go_component/... \
-            -//examples/go_component:calculator_docs \
             -//examples/wac_remote_compose/... \
             -//examples/wac_oci_composition/... \
             -//examples/wkg_integration/... \
@@ -213,14 +211,12 @@ jobs:
           else
             EXTRA_EXCLUDES=""
           fi
-          
+
           bazel build -- //... \
             -//examples/world_export/... \
             -//examples/multi_profile/... \
             -//examples/cpp_component/... \
             -//examples/js_component/... \
-            -//examples/go_component/... \
-            -//examples/go_component:calculator_docs \
             -//examples/wac_remote_compose/... \
             -//examples/wac_oci_composition/... \
             -//examples/wkg_integration/... \

MODULE.bazel

@@ -56,6 +56,11 @@ use_repo(go_sdk, "go_toolchains")
 
 register_toolchains("@go_toolchains//:all")
 
+# WASI WIT interface definitions
+wasi_wit_ext = use_extension("//wasm:extensions.bzl", "wasi_wit")
+wasi_wit_ext.init()
+use_repo(wasi_wit_ext, "wasi_io")  # Add your external repos here: , "my_external_wit"
+
 # WebAssembly toolchains
 wasm_toolchain = use_extension("//wasm:extensions.bzl", "wasm_toolchain")
 wasm_toolchain.register(