chore: dependency updates (presidio-analyzer, spacy, cryptography) and changelog policy fix

[overwrite00]

Merge pending dependency updates and changelog cleanup from develop:

• presidio-analyzer 2.2.363 -> 2.2.364, spacy 3.8.13 -> 3.8.14 (chore(deps)(deps): bump the minor-and-patch group with 2 updates #93): presidio-analyzer now only excludes spacy 3.8.14 for python_version>=3.14, so it installs cleanly on our Python 3.13 target and picks up spacy's model-download bugfix.
• cryptography 45.0.7 -> 49.0.0 (chore(deps)(deps): bump cryptography from 45.0.7 to 49.0.0 #94): resolves 4 open Dependabot security advisories (2 high, 1 medium, 1 low), including a vulnerable bundled OpenSSL and a missing SECT curve subgroup validation. The macOS x86_64 wheel removal in 49.0.0 has no practical impact (CI already builds only on macos-latest/arm64).
• CHANGELOG policy: consolidated the transient [2.1.0-beta.2] heading back under [Unreleased] so both branches only ever carry headings for released stable versions, avoiding future drift/conflicts between develop and main.
• Refreshed the dependency version table in DEVELOPMENT.md.

Verified in an isolated Python 3.13 environment with all three bumps combined: 27/27 tests pass (including the Fernet encrypt/decrypt round-trip), mypy unchanged (18 pre-existing errors, no regressions), and the app module loads correctly.