chore: remove leaked marketing/devrel/ files (block-forbidden-paths leak)

PR #1889 ("docs(blog): A2A Protocol deep-dive") landed two files under
the forbidden marketing/devrel/ path:

- marketing/devrel/phase34-platform-instructions-social-copy.md
- marketing/devrel/phase34-tool-trace-social-copy.md

The Block-forbidden-paths workflow correctly flagged both at PR-time
(run 24875689649 — failure at 06:28:20Z) but it was NOT in the required
status checks list on staging, so the PR merged anyway at 06:32:47Z.
The push-event run on staging then failed visibly (run 24875838257),
which is what surfaced this.

Two-part fix:

1. (this PR) Remove the leaked files. Authors can re-file the same
   content in Molecule-AI/internal under marketing/ if it's still needed.

2. (already done outside this PR) "Block forbidden paths" added to
   required_status_checks on staging branch protection so the next leak
   attempt gets blocked at PR-merge time, not after the fact.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

marketing/devrel/phase34-platform-instructions-social-copy.md

@@ -1,19 +0,0 @@
----
-title: "Platform Instructions: Governance at the System Prompt Level"
-date: 2026-04-23
-platform: linkedin
-author: Molecule AI
-og_image: ""
----
-
-Enterprise governance before the first agent turn executes.
-
-Platform Instructions: write policy rules once, enforce them everywhere — at the system prompt level.
-
-Global + workspace-scoped rules. wsAuth-gated resolve. No code deploys.
-
-Available on Enterprise plans.
-
-→ docs.molecule.ai/blog/govern-ai-fleet-system-prompt-level
-
-#AI #Enterprise #Governance #Security #Agents

marketing/devrel/phase34-tool-trace-social-copy.md

@@ -1,19 +0,0 @@
----
-title: "Tool Trace: Debugging Agents Like a Pro"
-date: 2026-04-23
-platform: x
-author: Molecule AI
-og_image: ""
----
-
-🔍 Tool Trace — now in every A2A response.
-
-See every tool your agent called → inputs, output previews, timing. Parallel calls handled correctly via run_id pairing.
-
-No sampling. No sidecar. No guesswork.
-
-Built into the protocol. Enabled by default.
-
-→ docs.molecule.ai/blog/ai-agent-observability-without-overhead
-
-#AI #DevOps #Agents #Observability #Claude