feat(14-02): add WaybackMachine + CommonCrawl recon sources

- WaybackMachineSource queries CDX API for historical snapshots
- CommonCrawlSource queries CC Index API for matching pages
- Both credentialless, rate-limited at 1 req/5s, RespectsRobots=true
- RegisterAll extended to 42 sources (40 Phase 10-13 + 2 Phase 14)
- Full httptest-based test coverage for both sources

pkg/recon/sources/wayback.go

@@ -0,0 +1,126 @@
+package sources
+
+import (
+	"bufio"
+	"context"
+	"fmt"
+	"net/http"
+	"net/url"
+	"strings"
+	"time"
+
+	"golang.org/x/time/rate"
+
+	"github.com/salvacybersec/keyhunter/pkg/providers"
+	"github.com/salvacybersec/keyhunter/pkg/recon"
+)
+
+// WaybackMachineSource implements recon.ReconSource against the Wayback Machine
+// CDX Server API. It queries web.archive.org/cdx/search/cdx for historical
+// snapshots of pages matching provider keywords (e.g. domains known to host
+// API key documentation or configuration files).
+//
+// RECON-ARCH-01: Each matching CDX record yields a Finding pointing at the
+// archived snapshot URL. The source is credentialless and always enabled.
+type WaybackMachineSource struct {
+	// BaseURL defaults to https://web.archive.org. Tests override with httptest URL.
+	BaseURL string
+	// Registry drives the keyword query list via BuildQueries.
+	Registry *providers.Registry
+	// Limiters is the shared recon.LimiterRegistry.
+	Limiters *recon.LimiterRegistry
+	// Client is the shared retry HTTP wrapper. If nil, a default is used.
+	Client *Client
+}
+
+// Compile-time assertion that WaybackMachineSource satisfies recon.ReconSource.
+var _ recon.ReconSource = (*WaybackMachineSource)(nil)
+
+func (s *WaybackMachineSource) Name() string          { return "wayback" }
+func (s *WaybackMachineSource) RateLimit() rate.Limit { return rate.Every(5 * time.Second) }
+func (s *WaybackMachineSource) Burst() int            { return 1 }
+func (s *WaybackMachineSource) RespectsRobots() bool  { return true }
+
+// Enabled always returns true: CDX API is unauthenticated.
+func (s *WaybackMachineSource) Enabled(_ recon.Config) bool { return true }
+
+// Sweep iterates provider keywords, queries the CDX API for each, and emits
+// a Finding for every archived snapshot URL returned. The CDX API returns
+// plain-text lines with space-separated fields; we extract the original URL
+// and timestamp to construct the full Wayback snapshot link.
+func (s *WaybackMachineSource) Sweep(ctx context.Context, _ string, out chan<- recon.Finding) error {
+	base := s.BaseURL
+	if base == "" {
+		base = "https://web.archive.org"
+	}
+	client := s.Client
+	if client == nil {
+		client = NewClient()
+	}
+
+	queries := BuildQueries(s.Registry, "wayback")
+	if len(queries) == 0 {
+		return nil
+	}
+
+	for _, q := range queries {
+		if err := ctx.Err(); err != nil {
+			return err
+		}
+
+		if s.Limiters != nil {
+			if err := s.Limiters.Wait(ctx, s.Name(), s.RateLimit(), s.Burst(), false); err != nil {
+				return err
+			}
+		}
+
+		// CDX API: output=text, fl=timestamp,original limits response to two fields per line.
+		// limit=50 keeps the response bounded per keyword.
+		endpoint := fmt.Sprintf("%s/cdx/search/cdx?url=*&output=text&fl=timestamp,original&limit=50&matchType=prefix&filter=statuscode:200&query=%s",
+			base, url.QueryEscape(q))
+		req, err := http.NewRequestWithContext(ctx, http.MethodGet, endpoint, nil)
+		if err != nil {
+			return fmt.Errorf("wayback: build req: %w", err)
+		}
+		req.Header.Set("Accept", "text/plain")
+
+		resp, err := client.Do(ctx, req)
+		if err != nil {
+			// Non-fatal: skip this keyword on transient errors.
+			continue
+		}
+
+		scanner := bufio.NewScanner(resp.Body)
+		for scanner.Scan() {
+			line := strings.TrimSpace(scanner.Text())
+			if line == "" {
+				continue
+			}
+			// CDX text output: "timestamp original-url"
+			parts := strings.SplitN(line, " ", 2)
+			if len(parts) < 2 {
+				continue
+			}
+			ts := parts[0]
+			origURL := parts[1]
+
+			snapshotURL := fmt.Sprintf("%s/web/%s/%s", base, ts, origURL)
+
+			f := recon.Finding{
+				ProviderName: "",
+				Source:       snapshotURL,
+				SourceType:   "recon:wayback",
+				Confidence:   "low",
+				DetectedAt:   time.Now(),
+			}
+			select {
+			case out <- f:
+			case <-ctx.Done():
+				_ = resp.Body.Close()
+				return ctx.Err()
+			}
+		}
+		_ = resp.Body.Close()
+	}
+	return nil
+}