fix(kyberforge): bridge apm content to Claude Code's flat plugin discovery

Claude Code's (and Copilot's) native plugin installer has zero awareness of
.apm/ nesting -- it convention-scans only flat skills/, agents/, commands/,
hooks.json at each plugin's root. Confirmed via strings on the installed
claude binary and live installs of git@holocron/gitea@holocron/kyberforge@
holocron, all reporting Skills(0) Agents(0) Hooks(0) post ADR-0015's apm
conversion. Root cause (apm_cli/core/plugin_manifest.py): apm's plugin.json
compiler deliberately strips skills/agents/commands keys, assuming the host
already auto-discovers those convention directories -- it has no model of
.apm/ being host-visible at all. Separately, apm's own bundle exporter
(apm_cli/bundle/plugin_exporter.py, behind `apm pack --format plugin`)
implements the correct .apm/ -> flat mapping, but only ever targeted
build/<name>-<version>/, a path nothing in marketplace.json's source: points
at.

scripts/sync-plugin-content.sh wraps that bundle exporter and copies its
agents/, skills/, commands/, instructions/, extensions/, and merged
hooks.json back into each plugin's own root as a second tracked
compiled-output category -- same governance status as
.claude-plugin/plugin.json: generated from .apm/, never hand-edited. tests/
subdirectories are excluded from the mirror (dev fixtures, not host-visible
runtime content; several hardcode a relative repo-root walk-up sized for the
.apm/-nested depth, which breaks when duplicated one level shallower).
Applied for real across all 6 plugins and verified two ways: `claude plugin
validate --strict` passes on every real plugin directory, and a live
`claude --plugin-dir <path> -p "list skills/agents"` behavioral test
confirms content is now actually discovered.

Also, from the same issue #90 review round:
- scripts/check-manifests.sh pointed at each plugin's root-level plugin.json
  (checking skills/hooks/mcpServers/agents pointer fields) -- that file was a
  stale near-duplicate of .claude-plugin/plugin.json nothing else read or
  wrote, now deleted across all 6 plugins. check-manifests.sh is rewritten to
  validate .claude-plugin/plugin.json instead, and drops the pointer-field
  checks entirely (nothing to check -- those fields are correctly absent by
  design). Content-presence drift is now check-plugin-content-sync's job, a
  new pre-push hook wired in .pre-commit-config.yaml.

docs/adr/0017 records the root cause and decision in full, including two
rejected alternatives (patching plugin.json's path fields directly -- apm's
compiler strips them on every run; pointing marketplace.json at apm pack's
build/ output -- a version-suffixed non-source directory nothing can install
from without an extra build step). ADR-0015 and CONTEXT.md are updated to
point at it.

Refs: #90

plugins/kyberforge/skills/apm-workflow/references/compile.md

@@ -0,0 +1,65 @@
+---
+topic: compile
+source_keys:
+  - context7-microsoft-apm
+---
+
+## Compile
+
+```bash
+apm compile                     # fails on skill/agent-only packages — see Gotchas
+apm compile --clean             # zero-write sanity check; use for skill/agent-only packages
+apm compile --clean --dry-run   # pure preview, no writes
+```
+
+Compiles `.apm/instructions/` + `.apm/agents/*.agent.md` primitives into consumer-side context files (AGENTS.md/CLAUDE.md CONTEXT files) for the deployment target, per the `compilation:` block in `apm.yml`. This is the consumer/deployment side — it is NOT the producer of `plugin.json`/`marketplace.json`; that's `apm pack`'s job (below). Run `apm compile` after any change to `.apm/instructions/`/`.apm/agents/` content or to `compilation:`/`targets:` in `apm.yml`.
+
+## Pack
+
+```bash
+apm pack --dry-run              # resolve and print; do not write
+apm pack --offline              # cached refs only
+apm pack --include-prerelease   # allow pre-release tags
+apm pack -v                     # per-entry resolution detail
+apm pack --marketplace=claude --json   # JSON output for CI pipelines
+```
+
+Bundles a producer package into a distributable artifact. Default to `--dry-run -v` first when packing something for the first time or after a dependency change — resolution errors surface before anything is written.
+
+### `.mcp.json` merge mechanics
+
+`apm pack` reads a package's root-level `.mcp.json` directly — no `dependencies.mcp` entry in `apm.yml` is needed for simple passthrough. Behavior is content-aware:
+
+- An empty `.mcp.json` (`{"mcpServers": {}}`) is NOT included in the packed output at all.
+- A populated one gets its `mcpServers` content merged directly into the compiled `plugin.json`, but only for the `claude` target.
+- The `copilot` target's compiled `plugin.json` OMITS `mcpServers` entirely — it isn't part of Copilot's plugin manifest schema.
+
+`dependencies.mcp` in `apm.yml` is for a different purpose — declaring a remote MCP-server package as an APM dependency — not local `.mcp.json` passthrough.
+
+### `includes: auto` and the packed bundle
+
+`includes: auto` does NOT sweep generic root-level passthrough files (README.md, docs/, sources.md, config files, etc.) into the `apm pack` distribution bundle (`build/<name>-<version>`) — only `.apm/` primitives, the compiled `plugin.json`, and the content-aware `.mcp.json` handling above make it into that bundle. This does not affect Claude Code's own plugin loading, which reads a plugin's working directory directly via its `source:` path in `marketplace.json`, not the `apm pack` bundle — but it matters for anyone relying on the packed bundle for distribution via `apm install`.
+
+Run `apm audit` after compile/pack, not before — audit scans deployed/compiled output, not the source `apm.yml` manifest; see `references/audit.md`.
+
+## Publish
+
+```bash
+apm publish --package acme/my-skill --dry-run -v
+apm publish --package acme/my-skill
+```
+
+Publishes a producer package (root containing `apm.yml`, `.apm/`, and optionally a `registries:` block) to a registry. Always dry-run with `-v` first — publishing is not trivially reversible once a version tag is claimed on a registry.
+
+## Run
+
+```bash
+apm run <script> [--param key=value]
+```
+
+Executes a named script defined under `scripts:` in `apm.yml`, with `--param` substituting values into the script's parameters.
+
+## Gotchas
+
+- Plain `apm compile` HARD-FAILS with exit 1 and `No instruction files found in .apm/ directory` on any package that has skills/agents but no `.apm/instructions/` content — the common case for a skill-only or skill+agent package. Use `apm compile --clean` as the zero-write sanity-check substitute: it sets `allow_empty=True` internally and exits 0 cleanly with zero writes; add `--dry-run` for a pure preview. `compile` ≠ `pack` — see above.
+- `claude plugin validate --strict` auto-scans every `.md` file directly under a compiled plugin's `agents/` directory and treats it as an agent definition requiring frontmatter, independent of any manifest declaration (an empirically observed Claude Code platform behavior, not an `apm` mechanic). A non-agent `.md` file (notes, provenance record, README) that ends up under `.apm/agents/` in the source tree will still fail validation once compiled to the `claude` target. Keep such files outside `.apm/agents/` (e.g. at the package root), regardless of what `apm.yml` declares.