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/gitea/skills/gitea-issues/README.md

@@ -0,0 +1,42 @@
+# gitea-issues
+
+Read and write Gitea issues — list, get, create, comment, close, and search — via the Gitea MCP server.
+
+## What it does
+
+This skill handles the issue lifecycle (`list_issues`, `issue_read`, `issue_write`, `search_issues`):
+listing repo issues, reading a single issue's details/comments/labels, creating an issue, updating
+its state, adding/editing comments, applying labels, and searching issues/PRs across repositories.
+The create flow closes out four enrichments deferred from issue #6 comment #848: label inference
+and milestone assignment (both by composing `gitea-labels-milestones`), an assignee workaround for
+the blocked `get_me` scope, and the "Depends on #N" dependency-linking convention. It supersedes the
+`issue`/`issue <N>`/`issue close <N>`/`issue comment <N>` dispatch in the old flat
+`plugins/bin/skills/gitea/SKILL.md`, removed per
+`docs/adr/0011-gitea-skill-deep-modules.md`.
+
+## Before you start
+
+Requires a Gitea MCP server configured with a token holding `write:issue` + `write:repository`.
+Requires a git remote named `origin` pointing at the Gitea instance, unless an orchestrating caller
+(e.g. `gitea-workflow`) already resolved `owner`/`repo` for you. Label and milestone management
+(creating/editing a label, creating/closing a milestone) is out of scope here — that's
+`gitea-labels-milestones`, which this skill composes rather than duplicates.
+
+## Usage
+
+```
+/gitea-issues
+```
+
+Describe your task: list issues, create one, get/comment/close a specific issue number, or search
+across repos. See `SKILL.md`'s dispatch table for the full set of recognized invocations.
+
+## Files
+
+| File | Purpose |
+|------|---------|
+| `SKILL.md` | Skill instructions for agents — dispatch table, Gotchas |
+| `references/issues.md` | Verified call signatures and mechanics for `list_issues`/`issue_read`/`issue_write` |
+| `references/search.md` | Verified call signature and mechanics for `search_issues` |
+| `references/enrichments.md` | Create-flow enrichments — label inference, milestone assignment, assignee workaround, dependency-linking convention |
+| `references/sources.md` | Research sources backing the issue guidance |