refactor: extract all hardcoded values to constants (v0.8.1)

Fix all 63 hardcoded value issues from Guardian self-check:
- Remove hardcoded Slack token from documentation
- Remove aws-sdk framework leak from domain layer
- Rename 4 pipeline files to verb-noun convention
- Extract 57 magic strings to SecretExamples.ts constants
- Update SecretViolation, SecretDetector, MagicStringMatcher
- Use typeof for TypeScript literal type in getSeverity()

Result: 0 issues in Guardian self-check (was 63)
All 566 tests passing, build successful

packages/guardian/src/domain/constants/SecretExamples.ts

@@ -0,0 +1,79 @@
+/**
+ * Secret detection constants
+ * All hardcoded strings related to secret detection and examples
+ */
+
+export const SECRET_KEYWORDS = {
+    AWS: "aws",
+    GITHUB: "github",
+    NPM: "npm",
+    SSH: "ssh",
+    PRIVATE_KEY: "private key",
+    SLACK: "slack",
+    API_KEY: "api key",
+    APIKEY: "apikey",
+    ACCESS_KEY: "access key",
+    SECRET: "secret",
+    TOKEN: "token",
+    PASSWORD: "password",
+    USER: "user",
+    BOT: "bot",
+    RSA: "rsa",
+    DSA: "dsa",
+    ECDSA: "ecdsa",
+    ED25519: "ed25519",
+    BASICAUTH: "basicauth",
+    GCP: "gcp",
+    GOOGLE: "google",
+    PRIVATEKEY: "privatekey",
+    PERSONAL_ACCESS_TOKEN: "personal access token",
+    OAUTH: "oauth",
+} as const
+
+export const SECRET_TYPE_NAMES = {
+    AWS_ACCESS_KEY: "AWS Access Key",
+    AWS_SECRET_KEY: "AWS Secret Key",
+    AWS_CREDENTIAL: "AWS Credential",
+    GITHUB_PERSONAL_ACCESS_TOKEN: "GitHub Personal Access Token",
+    GITHUB_OAUTH_TOKEN: "GitHub OAuth Token",
+    GITHUB_TOKEN: "GitHub Token",
+    NPM_TOKEN: "NPM Token",
+    GCP_SERVICE_ACCOUNT_KEY: "GCP Service Account Key",
+    SSH_RSA_PRIVATE_KEY: "SSH RSA Private Key",
+    SSH_DSA_PRIVATE_KEY: "SSH DSA Private Key",
+    SSH_ECDSA_PRIVATE_KEY: "SSH ECDSA Private Key",
+    SSH_ED25519_PRIVATE_KEY: "SSH Ed25519 Private Key",
+    SSH_PRIVATE_KEY: "SSH Private Key",
+    SLACK_BOT_TOKEN: "Slack Bot Token",
+    SLACK_USER_TOKEN: "Slack User Token",
+    SLACK_TOKEN: "Slack Token",
+    BASIC_AUTH_CREDENTIALS: "Basic Authentication Credentials",
+    API_KEY: "API Key",
+    AUTHENTICATION_TOKEN: "Authentication Token",
+    PASSWORD: "Password",
+    SECRET: "Secret",
+    SENSITIVE_DATA: "Sensitive Data",
+} as const
+
+export const SECRET_EXAMPLE_VALUES = {
+    AWS_ACCESS_KEY_ID: "AKIA1234567890ABCDEF",
+    AWS_SECRET_ACCESS_KEY: "wJalrXUtnFEMI/K7MDENG/bPxRfiCYEXAMPLEKEY",
+    GITHUB_TOKEN: "ghp_1234567890abcdefghijklmnopqrstuv",
+    NPM_TOKEN: "npm_abc123xyz",
+    SLACK_TOKEN: "xoxb-<token-here>",
+    API_KEY: "sk_live_XXXXXXXXXXXXXXXXXXXX_example_key",
+    HARDCODED_SECRET: "hardcoded-secret-value",
+} as const
+
+export const FILE_ENCODING = {
+    UTF8: "utf-8",
+} as const
+
+export const REGEX_ESCAPE_PATTERN = {
+    DOLLAR_AMPERSAND: "\\$&",
+} as const
+
+export const DYNAMIC_IMPORT_PATTERN_PARTS = {
+    QUOTE_START: '"`][^',
+    QUOTE_END: "`]+['\"",
+} as const