chore(release): kyberforge 1.5.0, marketplace 0.4.0

Why
---
The SessionStart freshness hook is a new kyberforge feature and was committed
without a version bump. It also cannot ship unbumped: apm's executable-trust
allow key is version-pinned, so `kyberforge#1.4.1` would have stopped matching
the moment the package version moved, silently blocking the very hook the entry
exists to authorise.

Implementation notes
-----------------
kyberforge 1.4.1 -> 1.5.0 (MINOR, new feature); marketplace and root manifest
0.3.4 -> 0.4.0, following the convention in bb9158d where a package bump carries
the marketplace version with it. The executables.allow key moves to
kyberforge#1.5.0 in the same commit. Compiled manifests regenerated with
`apm pack` plus both sync scripts.

A bare `apm pack` also writes build/ and a root .claude-plugin/plugin.json,
neither of which is repo content — the pre-push gate only ever runs pack with
--dry-run, so they had not appeared before. Both removed; build/ is now
gitignored so a future release does not stage it by accident.

Impact
------
Consumers pinning kyberforge see a MINOR bump. All 15 pre-push hooks pass,
including apm pack --check-clean, so compiled output matches the manifests.

ADR: 0019

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01X7GvKuJfy2WrdBmUttV4DT

apm.yml

@@ -1,5 +1,5 @@
 name: holocron
-version: 0.3.4
+version: 0.4.0
 description: AI development skills for Claude Code and GitHub Copilot CLI — factory, design, implement, review, and cross-cutting workflows.
 license: MIT
 
@@ -42,7 +42,7 @@ dependencies:
 # after a kyberforge release, check this first.
 executables:
   allow:
-    kyberforge#1.4.1:
+    kyberforge#1.5.0:
       hooks: true
       bin: true
 
@@ -52,7 +52,7 @@ marketplace:
   # top-level apm.yml description:/version: above are NOT inherited into the
   # compiled output despite being used elsewhere (e.g. by `apm audit`).
   description: AI development skills for Claude Code and GitHub Copilot CLI — factory, design, implement, review, and cross-cutting workflows.
-  version: 0.3.4
+  version: 0.4.0
   owner:
     name: Defame1297
     email: defame1297@rkdr.net
@@ -79,7 +79,7 @@ marketplace:
     - name: kyberforge
       description: Skills and agents for creating, maintaining, and managing a Claude Code / Copilot CLI plugin marketplace.
       source: ./plugins/kyberforge
-      version: 1.4.1
+      version: 1.5.0
       category: Developer Tools
 
     - name: bin