Modernize codebase (commit-by-commit)

[amylin1249]

Fixes #365 -- overall aims to modernize the codebase by removing old code practices while preserving all functionality (including adhering to version requirements)

Intend to be reviewed commit-by-commit:

1. Update pipes to native — %>% → R native pipe |> across R extensions.
2. update sapply — sapply() → vapply()/lapply() (type-safe / side-effect-appropriate).
3. Update pipes in prototype (unreleased) — same native-pipe migration as 1 for the unreleased prototype-content-with-issues-table.
4. Update to f strings — .format()/% → f-strings in Python extensions.
5. path update — os.path → pathlib in Python extensions.
6. simplify code blocks — pipe conversions that needed restructuring (nrow(.)→n(), dropped the format_table(x = .) placeholder) plus consolidated mutate() calls; behavior-preserving.
7. update typing — List[Price] → list[Price] builtin generic (FastAPI).
8. Misc cleanup — removed dead/obsolete comments, 1:n → seq_len(n), simplified redundant string literals.
9. add changelogs, bump versions — patch version bumps, refreshed file checksums, and CHANGELOG entries for every affected published extension.

[github-actions]

Extension release summary

🚀 Will release on merge

• portfolio-dashboard: 0.0.2 → 0.0.3
• portfolio-report: 0.0.1 → 0.0.2
• quarto-stock-report-r: 1.0.2 → 1.0.3
• quarto-website: 1.0.0 → 1.0.1
• runtime-version-scanner: 1.0.2 → 1.0.3
• stock-api-fastapi: 1.0.0 → 1.0.1
• stock-api-flask: 1.0.0 → 1.0.1
• stock-api-plumber: 1.0.0 → 1.0.1
• stock-dashboard-python: 1.0.0 → 1.0.1
• stock-report: 1.0.0 → 1.0.2
• top-5-income-share-bokeh: 1.0.0 → 1.0.1
• top-5-income-share-streamlit: 1.0.0 → 1.0.1
• usage-metrics-dashboard: 1.0.14 → 1.0.15

See the contributing guide for details.