chore(llm-security): v7.4.0 — examples + e2e suite minor

Bumps from v7.3.1 to v7.4.0. Purely additive surface — no scanner
or hook behavior changes, no breaking changes.

Headline content (already merged on main since v7.3.1):

- examples/ utvidelse — seven runnable demonstration walkthroughs
  shipped over three sessions (sesjon 1 pre-existing
  prompt-injection-showcase + lethal-trifecta-walkthrough,
  mcp-rug-pull, supply-chain-attack, poisoned-claude-md,
  bash-evasion-gallery, toxic-agent-demo, pre-compact-poisoning).
  Each is self-contained: README + fixture + run-script +
  expected-findings testable contract. State-isolation pattern
  (PID-suffixed JSONL or env-overrides like
  LLM_SECURITY_MCP_CACHE_FILE) keeps the user's real cache and
  /tmp state untouched.
- tests/e2e/ — three new suites totalling 45 tests:
  attack-chain.test.mjs (17), multi-session.test.mjs (9),
  scan-pipeline.test.mjs (19). Test count 1777 to 1822. These
  exercise the framework as a coordinated system rather than as
  isolated unit-tests.

Version sync (8 files):

- package.json
- .claude-plugin/plugin.json
- CLAUDE.md (header)
- README.md (badge + Recent versions tabellen new row)
- CHANGELOG.md (Unreleased to [7.4.0] - 2026-05-05 with summary)
- scanners/dashboard-aggregator.mjs VERSION constant
- scanners/ide-extension-scanner.mjs VERSION constant
- scanners/posture-scanner.mjs VERSION constant

Stabilization-stance unchanged. v8.0.0 remains the planned
deprecation-cleanup release. v7.x continues as the stable line.

Tests: 1822/1822 grønne lokalt etter bump.

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

plugins/llm-security/.claude-plugin/plugin.json

@@ -1,5 +1,5 @@
 {
   "name": "llm-security",
   "description": "Security scanning, auditing, and threat modeling for Claude Code projects. Detects secrets, validates MCP servers, assesses security posture, and generates threat models aligned with OWASP LLM Top 10.",
-  "version": "7.3.1"
+  "version": "7.4.0"
 }