feat/v06-batch converts 19 source/workflow files to CRLF and makes git diff --check report 11,788 errors

[alpCaner]

Found while reviewing

PR #352 at 1cab240df85d5896c5390697c069720ff2bb24d3 contains broad line-ending churn unrelated to the functional changes.

Measured against origin/dev:

19 changed files have CRLF line terminators
11,788 "trailing whitespace" findings from git diff --check

Affected files include .github/workflows/release.yml, python/tan/cli.py, doctor_cmd.py, flash_cmd.py, run_cmd.py, scaffold_cmd.py, several core modules, and parity/command tests.

This accounts for much of the apparent full-file replacement in a 105-file, ~38k-line review and makes actual changes substantially harder to audit. It also leaves the repository dependent on each tool preserving a mixed LF/CRLF state.

Acceptance criteria

• Restore the repository's intended line endings without changing file content.
• Add or confirm .gitattributes rules for Python, YAML, JSON, and shell sources.
• git diff --check origin/dev...HEAD is clean.
• The functional diff no longer contains full-file replacements caused only by line endings.

Related: PR #352.

[alpCaner]

Fixed on dev in ac79d4c (PR #352). dev IS this repo's default branch, so Closes does fire here -- but this issue was filed AFTER the PR body's closing-keyword list was written, so it was never in it. Closed by hand; a merged PR body cannot close retroactively.

* text=auto eol=lf at the top of .gitattributes plus git add --renormalize. git diff --check origin/dev...HEAD went 11,788 -> 0, and --ignore-cr-at-eol --stat listed .gitattributes and nothing else -- proving the other 33 files changed line endings and no content.