feat(pyproject): release v1.7.0 — Python pyproject.toml version bump

Add internal/pyproject package with ReadVersion and WriteVersion for
pyproject.toml files. Reads [project].version (PEP 621) first, then
falls back to [tool.poetry].version. Section boundaries are detected
via TOML's rule that headers always start at the beginning of a line
(\n[ pattern), so inline arrays with [ characters don't interfere.

Config follows the established multi-value pattern:
- python.pyproject_toml: single path (opt-in, no default)
- python.pyproject_tomls: list for monorepos (overrides single)
- --pyproject flag overrides pyproject_toml and clears pyproject_tomls

100% per-package statement coverage maintained across all 14 packages;
FuzzReadVersion and FuzzWriteVersion added per fuzzing guidelines.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

ROADMAP.md

@@ -86,5 +86,5 @@
 ## Future / backlog
 
 - ~~Gradle support (`build.gradle` / `build.gradle.kts`)~~ — ✓ shipped v1.6.0 (`internal/gradle`; Groovy + Kotlin DSL; multi-module via `gradle.build_files`; `--gradle` flag)
-- Python `pyproject.toml` version bump (`[project].version` and `[tool.poetry].version`; single and multi-path like Maven's `pom_paths`)
+- ~~Python `pyproject.toml` version bump (`[project].version` and `[tool.poetry].version`; single and multi-path like Maven's `pom_paths`)~~ — ✓ shipped v1.7.0 (`internal/pyproject`; PEP 621 + Poetry; `python.pyproject_tomls`; `--pyproject` flag)
 - Slack / Teams notification on release