fix: prevent false link-check failures and harden health/workflow errors

Address three review findings from the Go rewrite:\n\n- checker: update PartitionLinks to only classify HTTP(S) URLs as external links.\n  This skips markdown-relative targets (for example  and anchors) so\n  non-URL entries are no longer sent to HTTP validation and do not produce\n  deterministic "unsupported protocol scheme" failures.\n\n- health command: stop ignoring LoadHealthCache errors.\n  Return a user-facing "load cache" error when the cache file is unreadable\n  or invalid instead of allowing a nil cache panic on Merge.\n\n- broken links workflow: remove masked execution behavior from the link check\n  step. Capture awesome-docker check exit code, set has_errors=true on any\n  non-zero exit, and expose the exit code in the generated issue body so\n  checker failures are visible and cannot incorrectly close the tracking issue.\n\nTest coverage updates:\n- extend checker partition test to include markdown-relative/anchor targets\n  and verify they are not treated as external URLs.\n- add cache test for invalid YAML load failure.

.github/workflows/broken_links.yml

@@ -25,12 +25,21 @@ jobs:
       - name: Run Link Check
         id: link_check
         run: |
-          ./awesome-docker check > link_check_output.txt 2>&1 || true
-          if grep -q "broken links" link_check_output.txt; then
-            echo "has_errors=true" >> "$GITHUB_OUTPUT"
-          else
-            echo "has_errors=false" >> "$GITHUB_OUTPUT"
+          set +e
+          ./awesome-docker check > link_check_output.txt 2>&1
+          exit_code=$?
+          set -e
+
+          has_errors=false
+          if [ "$exit_code" -ne 0 ]; then
+            has_errors=true
           fi
+          if grep -qi "broken links" link_check_output.txt; then
+            has_errors=true
+          fi
+
+          echo "has_errors=$has_errors" >> "$GITHUB_OUTPUT"
+          echo "check_exit_code=$exit_code" >> "$GITHUB_OUTPUT"
         env:
           GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
 
@@ -41,8 +50,9 @@ jobs:
           script: |
             const fs = require('fs');
             const output = fs.readFileSync('link_check_output.txt', 'utf8');
+            const exitCode = '${{ steps.link_check.outputs.check_exit_code }}';
 
-            const issueBody = `# Broken Links Detected\n\nThe weekly link check found broken or inaccessible links.\n\n\`\`\`\n${output}\n\`\`\`\n\n## Action Required\n\n- Update the URL if the resource moved\n- Remove the entry if permanently unavailable\n- Add to \`config/exclude.yaml\` if a known false positive\n\n---\n*Auto-generated by broken_links.yml*`;
+            const issueBody = `# Broken Links Detected\n\nThe weekly link check found broken links or the checker failed to execute cleanly.\n\nChecker exit code: ${exitCode}\n\n\`\`\`\n${output}\n\`\`\`\n\n## Action Required\n\n- Update the URL if the resource moved\n- Remove the entry if permanently unavailable\n- Add to \`config/exclude.yaml\` if a known false positive\n- Investigate checker failures when exit code is non-zero\n\n---\n*Auto-generated by broken_links.yml*`;
 
             const issues = await github.rest.issues.listForRepo({
               owner: context.repo.owner,

cmd/awesome-docker/main.go

@@ -204,7 +204,10 @@ func healthCmd() *cobra.Command {
 			scored := scorer.ScoreAll(infos)
 			cacheEntries := scorer.ToCacheEntries(scored)
 
-			hc, _ := cache.LoadHealthCache(healthCachePath)
+			hc, err := cache.LoadHealthCache(healthCachePath)
+			if err != nil {
+				return fmt.Errorf("load cache: %w", err)
+			}
 			hc.Merge(cacheEntries)
 			if err := cache.SaveHealthCache(healthCachePath, hc); err != nil {
 				return fmt.Errorf("save cache: %w", err)

internal/cache/cache_test.go

@@ -78,6 +78,22 @@ func TestLoadHealthCacheMissing(t *testing.T) {
 	}
 }
 
+func TestLoadHealthCacheInvalidYAML(t *testing.T) {
+	dir := t.TempDir()
+	path := filepath.Join(dir, "health.yaml")
+	if err := os.WriteFile(path, []byte("entries:\n  - url: [not yaml"), 0644); err != nil {
+		t.Fatal(err)
+	}
+
+	hc, err := LoadHealthCache(path)
+	if err == nil {
+		t.Fatal("expected error for invalid YAML")
+	}
+	if hc != nil {
+		t.Fatal("expected nil cache on invalid YAML")
+	}
+}
+
 func TestMerge(t *testing.T) {
 	hc := &HealthCache{
 		Entries: []HealthEntry{

internal/checker/github.go

@@ -3,6 +3,7 @@ package checker
 import (
 	"context"
 	"fmt"
+	"net/url"
 	"strings"
 	"time"
 
@@ -43,12 +44,20 @@ func ExtractGitHubRepo(url string) (owner, name string, ok bool) {
 	return parts[0], parts[1], true
 }
 
-// PartitionLinks separates URLs into GitHub repos and external links.
+func isHTTPURL(raw string) bool {
+	u, err := url.Parse(raw)
+	if err != nil {
+		return false
+	}
+	return u.Scheme == "http" || u.Scheme == "https"
+}
+
+// PartitionLinks separates URLs into GitHub repos and external HTTP(S) links.
 func PartitionLinks(urls []string) (github, external []string) {
 	for _, url := range urls {
 		if _, _, ok := ExtractGitHubRepo(url); ok {
 			github = append(github, url)
-		} else {
+		} else if isHTTPURL(url) {
 			external = append(external, url)
 		}
 	}

internal/checker/github_test.go

@@ -41,6 +41,8 @@ func TestPartitionLinks(t *testing.T) {
 		"https://example.com/tool",
 		"https://github.com/moby/moby",
 		"https://github.com/user/repo/issues",
+		"dozzle",
+		"#projects",
 	}
 	gh, ext := PartitionLinks(urls)
 	if len(gh) != 2 {