fix(deps): bump pytest to >=9.0.3 to patch tmpdir CVE [#11,#12]

Dependabot flagged two open advisories for pytest < 9.0.3 (vulnerable
tmpdir handling) in:
- examples/spec-driven-development/requirements.txt
- examples/security-sandbox/requirements-sandbox.txt

These are illustrative requirements files for the examples — not on the
project's CI test path — but they're the version pins readers copy when
they clone an example. Strict == pins meant Dependabot couldn't auto-
upgrade them.

Loosened all pins to >= ranges (matching the style of requests>=2.32.4
already present in the sandbox file). Floors set to current versions
with known CVE fixes so new clones don't pick up known-vulnerable
versions on day one. Bumped at the same time:
- pytest-cov 4.1 -> 5.0
- pytest-mock 3.12 -> 3.14
- flake8 6.1 -> 7.0
- mypy 1.7 -> 1.11
- pre-commit 3.6 -> 3.7.1
- pydantic 2.5 -> 2.7.4
- ipython 8.17 -> 8.26
- rich 13.7 -> 13.7.1

Closes GHSA-7w4j (Dependabot alerts #11 and #12 on PaulDuvall/ai-development-patterns).

Author: Paul Duvall

examples/security-sandbox/requirements-sandbox.txt

@@ -1,12 +1,13 @@
 # AI Security Sandbox Dependencies
+# Floors set to versions with known CVE fixes; bump as advisories land.
 black>=24.3.0
-flake8==6.1.0
-mypy==1.7.0
-pytest==7.4.3
-pytest-cov==4.1.0
+flake8>=7.0.0
+mypy>=1.11.0
+pytest>=9.0.3
+pytest-cov>=5.0.0
 requests>=2.32.4
-pydantic==2.5.0
-ipython==8.17.2
+pydantic>=2.7.4
+ipython>=8.26.0
 jinja2>=3.1.6
-rich==13.7.0
-click==8.1.7
+rich>=13.7.1
+click>=8.1.7

examples/spec-driven-development/requirements.txt

@@ -1,20 +1,21 @@
 # Requirements for Specification Driven Development Example
 # Core testing and validation dependencies
+# Floors set to versions with known CVE fixes; bump as advisories land.
 
-pytest==7.4.3
-pytest-cov==4.1.0
-pytest-mock==3.12.0
+pytest>=9.0.3
+pytest-cov>=5.0.0
+pytest-mock>=3.14.0
 
 # Code quality and formatting
-black==26.3.1
-flake8==6.1.0
-mypy==1.7.0
+black>=26.3.1
+flake8>=7.0.0
+mypy>=1.11.0
 
 # Pre-commit hooks
-pre-commit==3.6.0
+pre-commit>=3.7.1
 
 # CLI and JSON handling
-click==8.1.7
+click>=8.1.7
 
 # Development dependencies
-ipython==8.17.2
+ipython>=8.26.0