chore: nuke post-migration dead code, deps, and broken Dockerfile fallback

- Drop ``wait_for_http_ready`` (FastAPI sidecar healthcheck) — only Caido
  TCP probe survives now. Removes the ``httpx`` import.
- Delete ``ListSitemapRenderer`` / ``ViewSitemapEntryRenderer`` — render
  UI for tools that disappeared with the Caido SDK migration.
- Drop ``scrubadub`` runtime dep — PII sanitizer was nuked previously
  but the dep stayed; resolve strips 18 transitives (numpy, scipy,
  scikit-learn, nltk, faker, …).
- Drop empty ``[project.optional-dependencies] sandbox`` section — last
  in-container Python dep migrated out.
- Drop unused mypy overrides (``pydantic_settings``, ``jwt``, ``gql``,
  ``scrubadub``, ``httpx``) and the stale ``fastapi`` isort group.
- Collapse Dockerfile's ``pipx install -r ... 2>/dev/null || venv``
  fallback into a direct venv install — pipx never accepted ``-r`` so
  the fallback was always firing.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

pyproject.toml

@@ -40,7 +40,6 @@ dependencies = [
   "textual>=6.0.0",
   "requests>=2.32.0",
   "cvss>=3.2",
-  "scrubadub>=2.0.1",
   "caido-sdk-client>=0.2.0",
   "aiohttp>=3.10.0",
 ]
@@ -48,9 +47,6 @@ dependencies = [
 [project.scripts]
 strix = "strix.interface.main:main"
 
-[project.optional-dependencies]
-sandbox = []
-
 [dependency-groups]
 dev = [
   "mypy>=1.16.0",
@@ -99,13 +95,8 @@ module = [
     "litellm.*",
     "rich.*",
     "jinja2.*",
-    "pydantic_settings.*",
-    "jwt.*",
-    "httpx.*",
-    "gql.*",
     "textual.*",
     "cvss.*",
-    "scrubadub.*",
     "docker.*",
     "caido_sdk_client.*",
     "aiohttp.*",
@@ -259,7 +250,7 @@ ignore = [
 force-single-line = false
 lines-after-imports = 2
 known-first-party = ["strix"]
-known-third-party = ["fastapi", "pydantic"]
+known-third-party = ["pydantic"]
 
 [tool.ruff.lint.pylint]
 max-args = 8
@@ -335,7 +326,7 @@ force_grid_wrap = 0
 use_parentheses = true
 ensure_newline_before_comments = true
 known_first_party = ["strix"]
-known_third_party = ["fastapi", "pydantic", "litellm"]
+known_third_party = ["pydantic", "litellm"]
 
 # ============================================================================
 # Bandit Configuration (Security Linting)