[Bug] Batch prompts use the caller's branch and previous commit instead of each repository

[404-Page-Found]

Description

batch passes each repository's staged diff into generateSuggestions(), but generateSuggestions() reads branch and previous-commit context from process.cwd() via getBranchName() and getLastCommitMessage().

When commit-echo batch <directory> --recursive is run from a non-Git parent directory, custom prompt variables {{branch}} and {{message}} therefore resolve to unknown / empty values for every repository. When the caller directory is itself a different Git repository, all batch items can inherit that unrelated repository's context.

Location

• src/commands/batch.ts:168-176 — per-repository call to generateSuggestions()
• src/llm/client.ts:45-54 — branch/message context is read without a repository path
• src/git/diff.ts:299-312 — getBranchName() and getLastCommitMessage() default to process.cwd()

Relevant code

// batch.ts
const result = await generateSuggestions(config, diff, profile, apiKey);

// llm/client.ts
const branch = getBranchName();
const message = getLastCommitMessage();

The per-repo diff is correct because the batch caller explicitly passes repoPath to getStagedDiff(repoPath), but the contextual prompt fields have no equivalent repository parameter.

Steps to Reproduce

1. Create two Git repositories under a non-Git directory, each on a distinct branch and with a distinct last commit subject.
2. Configure a custom prompt containing {{branch}} and/or {{message}}.
3. Run commit-echo batch <parent> --recursive.
4. Inspect the requests sent to the LLM.
5. The branch/previous-message fields do not come from the repository whose diff is being summarized.

Expected Behavior

Every batch request should resolve {{branch}} and {{message}} from the repository currently being processed.

Actual Behavior

Those fields are evaluated from the process working directory rather than the repository being processed.

Suggested Fix

Add an explicit cwd (or repository context object) to generateSuggestions() / prompt-context collection, and pass repoPath from batchCommand(). Add an end-to-end regression test with multiple repositories and distinct branch/message values.

Impact

Custom batch prompt templates can receive unrelated repository context, leading to misleading commit suggestions and incorrect project-specific instructions exactly where the command is supposed to process many repositories independently.

Reviewed against current main at 6c01ad0a853501e9617a3af0a5db3b515dd8ed53.

[404-Page-Found]

Triage: confirmed as a valid batch-mode bug.

• Priority: p2 — batch processing still works, but custom {{branch}} / {{message}} context can be wrong for every repository when the caller cwd is outside (or different from) the target repo. This is narrower than a core batch-processing outage.
• Root cause: batchCommand() passes repoPath to the Git diff/commit helpers, but generateSuggestions() and generateSuggestionsStream() still call getBranchName() / getLastCommitMessage() without a cwd, so Git resolves against process.cwd().
• Related work: PR fix(batch): reuse canonical Git diff logic and detect untracked changes #303 added cwd support to the canonical Git helpers, but the prompt-context helpers were left cwd-dependent. Issues [Bug] Batch mode skips repositories with unstaged/untracked changes #267/[Maintainability] Duplicated, divergent git logic in batch.ts vs git/diff.ts #268 were the adjacent batch cwd/duplication problems fixed by fix(batch): reuse canonical Git diff logic and detect untracked changes #303.
• Fix: add a repository cwd/context to the shared prompt-context path; pass repoPath from batch. Preserve the default cwd for existing single-repo call sites, and update the streaming variant too.
• Tests: add batch-level regression coverage using two repos with distinct branch names and last commit subjects, invoked from a non-Git parent (and ideally from an unrelated Git repo) and assert the outbound prompts use per-repo values.