feat: Forge-agnostic CLI abstraction for DAG workflows (gh → tea → bb → jira)

[tazmon95]

Problem

DAG workflows (e.g. archon-fix-github-issue) use gh CLI commands directly in bash nodes:

- id: fetch-issue
  bash: |
    gh issue view "$ISSUE_NUM" --json title,body,labels,comments,state,url,author

gh issue view --json uses GitHub's GraphQL API internally. When the same workflow runs against a Gitea repository, it fails:

HTTP 405: 405 Method Not Allowed (https://gitea.jtpa.net/api/graphql)

This blocks ALL DAG workflows on Gitea repos. The same problem will occur for Bitbucket and Jira when those adapters are built.

Current State

• The Gitea adapter (packages/adapters/src/community/forge/gitea/) handles webhooks and comments correctly via REST API
• The tea CLI is the Gitea equivalent of gh and is already used by the adapter
• But DAG workflow YAML files hardcode gh commands — there's no abstraction layer
• The workflows don't know what forge they're running against

Proposed Solution

Forge CLI Abstraction Layer

Introduce a thin abstraction that workflows use instead of gh/tea/bb directly.

Option A: Environment variable + wrapper script
The isolation/runner layer sets FORGE_CLI based on the repo's forge type (GitHub → gh, Gitea → tea, Bitbucket → bb) with a wrapper script that normalizes output.

Option B: Forge-agnostic helper command
A single archon-forge binary/script that detects forge type from git remote URL or env var, dispatches to the right CLI, and normalizes JSON output to a common schema.

Option C: API-first (no CLI dependency)
Skip CLIs entirely — use curl against the forge's REST API. The runner injects FORGE_API_URL, FORGE_TOKEN, REPO_OWNER, REPO_NAME as env vars.

Operations That Need Abstraction

Operation	gh command	tea equivalent
View issue	gh issue view N --json ...	tea issue view N or REST API
List issues	gh issue list --json ...	tea issue list or REST API
Create PR	gh pr create --draft	tea pr create or REST API
View PR	gh pr view --json ...	tea pr view or REST API
Add comment	gh issue comment N	tea comment create or REST API

Affected Workflows

All default DAG workflows with gh commands in bash nodes:

• archon-fix-github-issue.yaml — fetch-issue node
• archon-issue-review-full.yaml
• archon-pr-review-scope.yaml
• Any workflow with gh issue, gh pr, gh api

Reproduction

1. Create an issue on a Gitea repo connected to Archon
2. Comment @raca archon-fix-github-issue-dag
3. Observe: fetch-issue node fails with HTTP 405

We're happy to take this on and submit a PR. The Gitea adapter was contributed by us (PR #653).

— Fitzy 🐾