refactor(core): move dotenv helpers to core

[Mateus Zitelli (MateusZitelli)]

Summary

This is the foundational refactor for the env-var work:

• Move dotenv parse/serialize helpers from domains/flows to core
• Update existing callers to import from ~/core/dotenv.js
• Keep strict serializeDotenv() behavior: invalid env-var keys still throw
• Add serializeDotenvSkippingInvalid() for callers that intentionally want to drop unrepresentable keys

Why

Both flows pull and local flow runtime deps need the same dotenv parser/serializer. Keeping this in core avoids cross-domain imports and lets later PRs build on a neutral pure utility.

Tests

• bun run lint
• bun run typecheck
• bun run test src/core/dotenv.test.ts src/commands/flows/runDefaults.test.ts src/domains/flows/pull/envVars.test.ts

[coderabbitai]

No actionable comments were generated in the recent review. 🎉

ℹ️ Recent review info

⚙️ Run configuration

Configuration used: Organization UI

Review profile: ASSERTIVE

Plan: Pro Plus

Run ID: 2133c552-0f68-41ba-910e-17f00a2eda38

📥 Commits

Reviewing files that changed from the base of the PR and between d7181e6 and e229206.

📒 Files selected for processing (8)

• .changeset/pull-skip-invalid-dotenv-keys.md
• src/core/messages/flows.ts
• src/domains/flows/pull/envVars.test.ts
• src/domains/flows/pull/envVars.ts
• src/domains/flows/pull/handler.test.ts
• src/domains/flows/pull/handler.ts
• src/domains/flows/pull/stage.test.ts
• src/domains/flows/pull/stage.ts

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Walkthrough

The PR adds graceful handling of invalid environment variable keys during flows pull. src/core/dotenv.ts gains an internal isDotenvKey predicate and a new exported serializeDotenvSkippingInvalid function that partitions variables into valid and invalid keys, serializes only the valid ones, and returns both the dotenv content string and a skippedKeys array. serializeDotenv is refactored to use isDotenvKey without behavioral change.

writeEnvFile in src/domains/flows/pull/envVars.ts switches from serializeDotenv to serializeDotenvSkippingInvalid, changes its return type to Promise<{ skippedKeys: readonly string[] }>, and only writes .env when the serialized content is non-empty. The skipped keys are then threaded upward through stageBundle (which gains a skippedEnvVarKeys field and adjusts envVarCount to exclude them) and handleFlowsPull (which emits a UI warning and includes skippedEnvVarKeys in JSON output). Dotenv imports are consolidated from ~/domains/flows/dotenv.js to ~/core/dotenv.js, and a new message formatter and changeset document the feature.

Estimated code review effort

🎯 3 (Moderate) | ⏱️ ~25 minutes

🚥 Pre-merge checks | ✅ 4

✅ Passed checks (4 passed)

Check name	Status	Explanation
Title check	✅ Passed	The title clearly describes the main change: moving dotenv helpers to core. It uses imperative mood, is concise (43 characters), follows conventional-commit format, and directly reflects the primary refactoring objective.
Description check	✅ Passed	The pull request description includes all required sections: summary of changes, rationale (why), and concrete test commands. However, the description lacks the optional linked issues line and formal checklist structure from the template.
Linked Issues check	✅ Passed	Check skipped because no linked issues were found for this pull request.
Out of Scope Changes check	✅ Passed	Check skipped because no linked issues were found for this pull request.

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---

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[coderabbitai]

Actionable comments posted: 1

🤖 Prompt for all review comments with AI agents

Verify each finding against current code. Fix only still-valid issues, skip the
rest with a brief reason, keep changes minimal, and validate.

Inline comments:
In `@src/domains/flows/pull/envVars.ts`:
- Line 6: The import statement is currently using the strict `serializeDotenv`
function which throws errors on non-POSIX keys and aborts .env file generation.
Replace this import with `serializeDotenvSkippingInvalid` instead, then locate
all usages of `serializeDotenv` in this file and switch them to use
`serializeDotenvSkippingInvalid` so that invalid keys are skipped rather than
causing failures. Make sure the returned `content` from the skip-invalid
serializer is properly written to the .env file.

🪄 Autofix (Beta)

Fix all unresolved CodeRabbit comments on this PR:

• Push a commit to this branch (recommended)
• Create a new PR with the fixes

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ℹ️ Review info

⚙️ Run configuration

Configuration used: Organization UI

Review profile: ASSERTIVE

Plan: Pro Plus

Run ID: 8f75e6e4-0e2b-4d0c-8331-a639d20dc19b

📥 Commits

Reviewing files that changed from the base of the PR and between adfc74e and d7181e6.

📒 Files selected for processing (4)

• src/commands/flows/loadEnvFile.ts
• src/core/dotenv.test.ts
• src/core/dotenv.ts
• src/domains/flows/pull/envVars.ts