fix(init): create start.prompt.md and fix next steps panel (#603)

[sergio-sisternes-epam]

Summary

Fixes #603 — apm init showed a Next Steps panel that directed users through an incorrect workflow. Following the instructions led to a dead end because start.prompt.md was never created and apm compile was referenced incorrectly.

Changes

1. Create start.prompt.md during init

• Regular (non-plugin) projects now get a minimal start.prompt.md with frontmatter
• Brownfield safety: existing start.prompt.md files are never overwritten
• Plugin mode (--plugin) does NOT create start.prompt.md
• Written with encoding="utf-8" for Windows compatibility

2. Fix Next Steps panel

• Removed: Compile agent context: apm compile (unrelated to apm run)
• Added: Edit your prompt: start.prompt.md
• The workflow now works end-to-end: init -> setup runtime -> edit prompt -> run

3. Updated Created Files table

• start.prompt.md now appears in the Created Files table when generated

Files Changed

• src/apm_cli/commands/init.py — Create start.prompt.md, fix next steps, update files table
• tests/unit/test_init_command.py — 5 new tests + 4 updated tests
• tests/unit/test_init_plugin.py — 1 new test (plugin mode doesn't create start.prompt.md)
• CHANGELOG.md — Add fix entry

Testing

All 3795 tests pass (39/39 init-specific tests pass).

[Copilot]

Pull request overview

Fixes the apm init -> apm run start onboarding flow by ensuring a runnable starter prompt exists and updating the printed Next Steps to match the intended workflow.

Changes:

• Create start.prompt.md during apm init for non-plugin projects (without overwriting existing files).
• Update the Next Steps panel to remove the unrelated apm compile step and direct users to edit start.prompt.md.
• Update and add unit tests, and add a changelog entry for the fix.

Reviewed changes

Copilot reviewed 4 out of 4 changed files in this pull request and generated 4 comments.

File	Description
src/apm_cli/commands/init.py	Creates start.prompt.md, updates Created Files output, and fixes Next Steps messaging.
tests/unit/test_init_command.py	Updates existing init tests and adds new coverage for the starter prompt and next-steps output.
tests/unit/test_init_plugin.py	Adds coverage ensuring plugin mode does not create start.prompt.md.
CHANGELOG.md	Adds an Unreleased “Fixed” entry describing the init onboarding fix.

[danielmeppiel]

Thanks for tackling #603 — the bug is real and the current Next Steps panel is genuinely broken (verified locally). Requesting changes because the shape of the fix conflicts with PR #18's design contract, and there's a cleaner reframe that resolves #603 without reintroducing scaffolding.

The conflict with PR #18

PR #18 established that apm init is brownfield-clean / npm-parity: it does NOT scaffold content files into the repo. The contract is "one apm.yml, nothing else." Re-adding start.prompt.md creation — even with brownfield-safety guards — silently reverses that decision and re-opens the scaffolding question we deliberately closed.

The right reframe

The bug isn't "we forgot to create start.prompt.md." It's "the panel teaches a workflow (apm run start) that doesn't match where APM's value lands today." Drop apm run start from the panel entirely; that's the source of the dead-end. Reframe around the install workflow, which is what 5 rounds of multi-PM panel research converged on as the actual high-value first-touch.

Recommended panel (every command verified working in a sandbox against current main):

Next Steps:
  * Install a skill:                apm install github/awesome-copilot/skills/documentation-writer
  * Install a marketplace plugin:   apm marketplace add github/awesome-copilot && apm install frontend-web-dev@awesome-copilot
  * Install a versioned package:    apm install microsoft/apm-sample-package#v1.0.0
  * Author your own plugin:         apm pack --format plugin

  Docs: https://microsoft.github.io/apm  |  Star: https://github.com/microsoft/apm

Per-line role:

• L1: virtual-path moat (any skill from any GitHub repo, no manifest required) — what no competitor can do
• L2: industry parity (brew-tap / VS Code / Claude marketplace 2-step), chained as one user action so it's a complete demo
• L3: supply-chain story — #v1.0.0 shows version pinning, and this install demonstrates transitive deps live (verified: pulls awesome-copilot/skills/review-and-refactor automatically). This is where apm.yml format earns its keep
• L4: authoring entrypoint — turns consumers into producers
• Footer: community CTA following the bun/uv/deno pattern

Three different verbs (Install / Install / Author) so the eye doesn't glaze on lines that all look the same.

Asks to land this in this PR

1. Drop the start.prompt.md creation logic (the write path and brownfield-safety guards). Honor the PR #18 contract.
2. Replace the Next Steps panel with the v5 shape above.
3. Drop apm run start from the panel. It's the source of the dead-end. The apm run workflow stays valid in docs; it's not the first-touch surface today.
4. Keep your test additions — the panel-content tests are still valuable; just update assertions to match the new lines.
5. While you're in there, also fix the related doc drift in docs/src/content/docs/introduction/key-concepts.md:16 and docs/src/content/docs/getting-started/first-package.md — both still reference scaffolded .apm/ trees that haven't existed since PR #18.

Happy to pair on the rewrite or take it on directly if you'd prefer. The bug is real, the fix is owed to the user, and your investigation pinpointed exactly what's broken — we just need to land it in a way that honors PR #18.