docs(install): catch additional active doc-link refs in guides + blog (#37 follow-up)

Follow-up to commit d05d92b: my first sweep filtered out only
issues/pull/commit/releases URLs but missed several /tree/<branch>/...
and active-mention paths in guides/.

Additional 5 edits across 4 files:
- guides/remote-workspaces.md:151,152 — molecule-sdk-python links
  (PUBLIC) migrated to Gitea; /tree/main → /src/branch/main path-shape.
- guides/external-workspace-quickstart.md:223 — design-doc link in
  internal/ + tracking-issue link to molecule-core/issues. Internal is
  PRIVATE; logged-in users see it; better than stale github 404.
- guides/skill-catalog.md:68,174 — molecule-ai/skills repo doesn't
  exist on Gitea (404). Replaced with placeholder note pointing at
  internal issue tracker for canonical submission path until skills
  repo is recreated/located. Filed as implicit parked follow-up.
- docs/marketing/blog/2026-04-20-...mcp.md:240 — GitHub Discussions
  link (Discussions don't have a Gitea equivalent today). Replaced
  with issue-tracker link.

Still LEFT AS-IS (per Q3): 90 historical PR/issue cross-refs in
changelog.mdx, plus changelog.mdx:349 'Documentation Specialist'
meta-narrative author attribution link, plus 2 incident-narrative
git clone --mirror commands in INCIDENT_LOG.md (those describe a
historical incident response, not active install instructions).

Refs: molecule-ai/internal#37, molecule-ai/internal#38

content/docs/guides/external-workspace-quickstart.md

@@ -220,7 +220,7 @@ Push mode (this guide) works today but requires an inbound-reachable URL — whi
 
 Your agent makes only outbound HTTPS calls to the platform, pulling messages from an inbox queue and posting replies back. Works behind any NAT/firewall, tolerates offline laptops, no tunnel needed.
 
-See the [design doc](https://github.com/Molecule-AI/internal/blob/main/product/external-workspaces-polling.md) (internal) and [implementation tracking issue](https://github.com/Molecule-AI/molecule-core/issues?q=polling+mode) once opened.
+See the [design doc](https://git.moleculesai.app/molecule-ai/internal/src/branch/main/product/external-workspaces-polling.md) (internal) and the implementation tracking issue (search `polling+mode` on the [molecule-core issue tracker](https://git.moleculesai.app/molecule-ai/molecule-core/issues)).
 
 ---
 

content/docs/guides/remote-workspaces.md

@@ -148,5 +148,5 @@ The agent appears on the canvas with a **purple REMOTE badge** within seconds. F
 ## Next Steps
 
 - **[External Agent Registration Guide →](/docs/guides/external-agent-registration)** — full endpoint reference, Python + Node.js examples, troubleshooting
-- **[molecule-sdk-python →](https://github.com/Molecule-AI/molecule-sdk-python)** — SDK source, `RemoteAgentClient` API docs
-- **[SDK Examples →](https://github.com/Molecule-AI/molecule-sdk-python/tree/main/examples/remote-agent)** — `run.py` demo script, annotated walkthrough
+- **[molecule-sdk-python →](https://git.moleculesai.app/molecule-ai/molecule-sdk-python)** — SDK source, `RemoteAgentClient` API docs
+- **[SDK Examples →](https://git.moleculesai.app/molecule-ai/molecule-sdk-python/src/branch/main/examples/remote-agent)** — `run.py` demo script, annotated walkthrough

content/docs/guides/skill-catalog.md

@@ -65,7 +65,7 @@ molecule skills install arxiv-research --from community
 
 Community skills are reviewed by the Molecule AI team before being
 listed. Submit a skill for review by opening a PR against
-[`molecule-ai/skills`](https://github.com/Molecule-AI/skills).
+`molecule-ai/skills` (repo location TBD post-2026-05-06 GitHub-org-suspension; check the [internal issue tracker](https://git.moleculesai.app/molecule-ai/internal/issues) for the canonical submission path).
 
 ## Installing via config.yaml
 
@@ -171,7 +171,7 @@ molecule skills bundle my-custom-skill --output ./org-templates/my-role/
 ```
 
 **Publishing to the community:** Open a PR against
-[`molecule-ai/skills`](https://github.com/Molecule-AI/skills) with a
+`molecule-ai/skills` (repo location TBD post-2026-05-06 GitHub-org-suspension; check the [internal issue tracker](https://git.moleculesai.app/molecule-ai/internal/issues) for the canonical submission path) with a
 complete skill package. Community skills are reviewed for security and
 correctness before listing.
 

docs/marketing/blog/2026-04-20-how-to-add-browser-automation-to-ai-agents-with-mcp.md

@@ -237,4 +237,4 @@ Once your agent is connected to MCP, it stops being a chatbot with a scrollable
 
 ---
 
-*Have questions or want to share what you're building with MCP? Open a discussion on [GitHub Discussions](https://github.com/Molecule-AI/molecule-core/discussions) or file an issue with the `enhancement` label.*
+*Have questions or want to share what you're building with MCP? File an issue with the `enhancement` label on the [molecule-core issue tracker](https://git.moleculesai.app/molecule-ai/molecule-core/issues).*