feat(08-01): add pkg/dorks foundation (schema, loader, registry, executor)

- Dork schema with Validate() mirroring provider YAML pattern
- go:embed loader tolerating empty definitions tree
- Registry with List/Get/Stats/ListBySource/ListByCategory
- Executor interface + Runner dispatch + ErrSourceNotImplemented
- Placeholder definitions/.gitkeep and repo-root dorks/.gitkeep
- Full unit test coverage for registry, validation, and runner dispatch

pkg/dorks/schema.go

@@ -0,0 +1,80 @@
+// Package dorks provides YAML-embedded dork definitions and per-source
+// executors for the KeyHunter dork engine. The package mirrors the
+// pkg/providers pattern: dorks are authored as YAML files under
+// pkg/dorks/definitions/{source}/*.yaml and compiled into the binary via
+// go:embed, then loaded into an in-memory Registry at startup.
+package dorks
+
+import (
+	"fmt"
+	"strings"
+)
+
+// Dork is a single dork definition loaded from a YAML file under
+// pkg/dorks/definitions/{source}/*.yaml.
+type Dork struct {
+	ID          string   `yaml:"id"`
+	Name        string   `yaml:"name"`
+	Source      string   `yaml:"source"`   // github|google|shodan|censys|zoomeye|fofa|gitlab|bing
+	Category    string   `yaml:"category"` // frontier|specialized|infrastructure|emerging|enterprise
+	Query       string   `yaml:"query"`
+	Description string   `yaml:"description"`
+	Tags        []string `yaml:"tags"`
+}
+
+// ValidSources enumerates the dork source backends recognised by the engine.
+// Executors for most of these arrive in later phases (OSINT 9-16); the
+// foundation plan only wires the GitHub executor live.
+var ValidSources = []string{
+	"github",
+	"google",
+	"shodan",
+	"censys",
+	"zoomeye",
+	"fofa",
+	"gitlab",
+	"bing",
+}
+
+// ValidCategories enumerates the dork taxonomy buckets used for filtering.
+var ValidCategories = []string{
+	"frontier",
+	"specialized",
+	"infrastructure",
+	"emerging",
+	"enterprise",
+}
+
+// Validate returns a non-nil error when the dork is missing required fields
+// or declares an unknown source.
+func (d Dork) Validate() error {
+	if strings.TrimSpace(d.ID) == "" {
+		return fmt.Errorf("dork: id is required")
+	}
+	if strings.TrimSpace(d.Source) == "" {
+		return fmt.Errorf("dork %q: source is required", d.ID)
+	}
+	if strings.TrimSpace(d.Query) == "" {
+		return fmt.Errorf("dork %q: query is required", d.ID)
+	}
+	if !contains(ValidSources, d.Source) {
+		return fmt.Errorf("dork %q: source %q is not one of %v", d.ID, d.Source, ValidSources)
+	}
+	return nil
+}
+
+// Stats holds aggregate counts over a Registry, returned by Registry.Stats.
+type Stats struct {
+	Total      int
+	BySource   map[string]int
+	ByCategory map[string]int
+}
+
+func contains(haystack []string, needle string) bool {
+	for _, h := range haystack {
+		if h == needle {
+			return true
+		}
+	}
+	return false
+}