fix: remove forced branching from Bash guidance

[AdhereZ]

Change

The Bash tool description instructed the agent to create a branch before committing or pushing from the default branch, even when the user intended to use the current branch. Remove that unconditional instruction while retaining the requirement to commit or push only when the user asks. Branching decisions remain governed by the user's request and repository instructions.

Fixes #356.

Validation

• PASS: git diff --check.
• PASS: pnpm verify (full profile) on clean commit d1a1885e21790547cdf9c5428a752dbe4b429cf0, macOS arm64, Node.js 22.22.3; all 15 applicable gates passed.
• Performance: basic CI coverage; no performance-sensitive implementation changes. CI performance results are pending.
• NOT RUN locally: Windows/Linux validation, npm release-package installation, and live-model behavior acceptance. Windows and release-package gates were intentionally skipped by the full profile on this host.

Publication and contribution checks

• I have permission to contribute these changes under the existing applicable licenses. No material was imported and existing notices are preserved.
• No credentials, account data, real user content, internal source history or private review material is included.
• No files or tests were added, removed, or renamed; source inventory regeneration is not needed.
• No shared English/Chinese documentation changes are required. Offline checks are not presented as live-service acceptance.

Maintainer handoff

Publication scope or license changes: none.

Shared-source port: pending.

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