fix: SPDX headers in CLAUDE.md; delegate SerializableBranch deserialization to from_gitmodules

[Copilot]

Two review-driven fixes: missing license headers in CLAUDE.md and a deserialization gap in SerializableBranch that silently accepted invalid input.

Changes

• CLAUDE.md: Restore SPDX FileCopyrightText + LicenseIdentifier header block (HTML comment, matching README.md/CONTRIBUTING.md convention).

• SerializableBranch::deserialize: Delegate to from_gitmodules instead of FromStr.

  • FromStr accepted empty/whitespace strings, producing Name("") silently.
  • from_gitmodules trims input, rejects empty/whitespace with Err(()), and matches the live superproject branch name as a CurrentInSuperproject alias.

// Before: FromStr accepted "" → Name(""), no trimming
SerializableBranch::from_str(&s)
    .map_err(|_| serde::de::Error::custom(...))

// After: from_gitmodules trims, rejects empty, handles superproject alias
SerializableBranch::from_gitmodules(&s)
    .map_err(|_| serde::de::Error::custom(...))

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Just as a heads up, I was blocked by some firewall rules while working on your feedback. Expand below for details.

Warning

Firewall rules blocked me from connecting to one or more addresses (expand for details)

I tried to connect to the following addresses, but was blocked by firewall rules:

• invalid-host
  • Triggering command: /home/REDACTED/work/submod/submod/target/debug/submod /home/REDACTED/work/submod/submod/target/debug/submod add git@invalid-host:user/repo.git --name invalid-test --path lib/invalid rgo/bin/git . (dns block)
  • Triggering command: /usr/bin/ssh /usr/bin/ssh -o SendEnv=GIT_PROTOCOL git@invalid-host git-upload-pack 'user/repo.git' deinit --all de/node/bin/git (dns block)
• nonexistent.domain.invalid
  • Triggering command: /home/REDACTED/work/submod/submod/target/debug/submod /home/REDACTED/work/submod/submod/target/debug/submod add REDACTED --name invalid-test --path lib/invalid /home/REDACTED/.local/bin/git ork test@example.comconfig k/_temp/ghcca-nouser.email git conf�� user.name Test User rgo/bin/git user.email test@example.comconfig /usr/local/.ghcuuser.email git (dns block)
  • Triggering command: /usr/lib/git-core/git-remote-http /usr/lib/git-core/git-remote-http origin REDACTED git subm�� deinit --all tnet/tools/git HEAD nuke_reinit.git k/submod/submod/--all git comm�� -m Initial commit /usr/local/.ghcup/bin/git -m Add dev featuresconfig git git (dns block)
• nonexistent.invalid.domain.test
  • Triggering command: /home/REDACTED/work/submod/submod/target/debug/submod /home/REDACTED/work/submod/submod/target/debug/submod add REDACTED --name timeout-test --path lib/timeout e config_test_workgit main e git clea�� e/git-submodule git tnet/tools/git git git git git (dns block)
  • Triggering command: /usr/lib/git-core/git-remote-http /usr/lib/git-core/git-remote-http origin REDACTED git comm�� -m Add test content target/debug/submod -m Add test contentconfig /usr/bin/git target/debug/subtest@example.com conf�� d/repo.git protocol.file.allow nfig/composer/vendor/bin/git --global (dns block)

If you need me to access, download, or install something from one of these locations, you can either:

• Configure Actions setup steps to set up my environment, which run before the firewall is enabled
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Pull request overview

This PR updates config branch deserialization to use the same parsing rules as .gitmodules conversion and adds SPDX headers to documentation, as follow-up work to PR #33’s review feedback.

Changes:

• Delegate SerializableBranch deserialization to GitmodulesConvert::from_gitmodules() and tighten behavior around empty/whitespace values.
• Add SPDX header block to CLAUDE.md.

Reviewed changes

Copilot reviewed 2 out of 2 changed files in this pull request and generated 2 comments.

File	Description
src/options.rs	Adjusts SerializableBranch deserialization to share .gitmodules parsing logic and error on invalid inputs.
CLAUDE.md	Adds SPDX header block in the repo’s standard Markdown format.

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