feat(skills): expand skill family — agentforge-template-author + agentforge-debug + release flow + install-command fix

[mandarnilange]

Summary

Closes P46-T6, T7, T9, T10, T11 — consolidates everything left in P46 except the manual validation (T8, retained by user) and the wait-and-watch skills.sh listing (T12).

New skills (round out the agentforge-* family)

• `agentforge-template-author` — guides contributors adding a new shipped template under `packages/{core,platform}/src/templates/`. Covers scope check, package selection (with the cross-package import rule), agent set, prompts, schemas, `template.json` manifest (validated against `isValidManifest` in the registry), README, and required parse tests against the Zod schemas in `packages/core/src/definitions/parser.ts`.
• `agentforge-debug` — triages stuck or failing pipeline runs from symptom → state inspection → root-cause class → fix path. Read-first discipline (never mutates state until run state is read). Reference docs cite the actual domain-model enums (`PipelineRunStatus`, `AgentRunRecordStatus`, `AgentRunExitReason`, `GateStatus`, `NodeStatus`).

Release flow

• Top-level `skills/CHANGELOG.md` with semver bump policy (major = trigger conditions / file structure changed; minor = additive prose, new reference docs; patch = typo / link / cheat-sheet fixes) and the release flow (validate → bump version → per-skill changelog → top-level changelog → PR).
• Per-skill `CHANGELOG.md` for all three skills documenting 0.1.0.

Install-command fix + gitignore

• `README.md` and `skills/README.md`: corrected `npx skills add mandarnilange/agentforge/agentforge-workflow` → `npx skills add mandarnilange/agentforge` (the third path segment is interpreted as a directory inside the repo, not a skill-name filter — verified locally). Tree-URL alternative documented for single-skill installs.
• `.gitignore`: ignore `.claude/`, `.agents/`, `CLAUDE.md`, `skills-lock.json`. Untracked `.claude/scheduled_tasks.lock` that was previously committed by mistake.

Cross-links

• `skills/README.md` adds an audience column and lists all three skills.
• README's "Agent Skills" section becomes a 3-row table; install command stays `mandarnilange/agentforge` (picks up all three at once).

Pending in P46 (out of scope here)

• P46-T8 — End-to-end manual validation in a fresh coding-agent session (user-driven; the user explicitly retained this).
• P46-T12 — Confirm skills.sh listing once install telemetry accrues (passive; tracked over ~4 weeks).

Test plan

• `npm run skills:validate` passes — frontmatter valid for all three skills (`agentforge-debug`, `agentforge-template-author`, `agentforge-workflow`).
• `npx biome check .` clean.
• Working tree finally clean (no more `.claude/scheduled_tasks.lock` drift).
• CI `Publish Skills` workflow turns green.
• Manually fire each skill in a fresh session against a representative prompt:
  • `agentforge-workflow`: "design an AgentForge pipeline for PR triage"
  • `agentforge-template-author`: "contribute a new template for ML-pipeline scaffolding"
  • `agentforge-debug`: "my pipeline run is stuck at phase 3, agent is failing repeatedly"

Supersedes

#10 — closed; its commits are cherry-picked here as `f28c78d` and `a7ae72a`.