fix(honcho): isolate session routing for multi-user gateway (#1500)

Salvaged from PR #1470 by adavyas.

Core fix: Honcho tool calls in a multi-session gateway could route to
the wrong session because honcho_tools.py relied on process-global
state. Now threads session context through the call chain:
  AIAgent._invoke_tool() → handle_function_call() → registry.dispatch()
  → handler **kw → _resolve_session_context()

Changes:
- Add _resolve_session_context() to prefer per-call context over globals
- Plumb honcho_manager + honcho_session_key through handle_function_call
- Add sync_honcho=False to run_conversation() for synthetic flush turns
- Pass honcho_session_key through gateway memory flush lifecycle
- Harden gateway PID detection when /proc cmdline is unreadable
- Make interrupt test scripts import-safe for pytest-xdist
- Wrap BibTeX examples in Jekyll raw blocks for docs build
- Fix thread-order-dependent assertion in client lifecycle test
- Expand Honcho docs: session isolation, lifecycle, routing internals

Dropped from original PR:
- Indentation change in _create_request_openai_client that would move
  client creation inside the lock (causes unnecessary contention)

Co-authored-by: adavyas <adavyas@users.noreply.github.com>

skills/research/arxiv/SKILL.md

@@ -114,6 +114,7 @@ curl -s "https://export.arxiv.org/api/query?id_list=2402.03300,2401.12345,2403.0
 
 After fetching metadata for a paper, generate a BibTeX entry:
 
+{% raw %}
 ```bash
 curl -s "https://export.arxiv.org/api/query?id_list=1706.03762" | python3 -c "
 import sys, xml.etree.ElementTree as ET
@@ -139,6 +140,7 @@ print(f'  url       = {{https://arxiv.org/abs/{raw_id}}}')
 print('}')
 "
 ```
+{% endraw %}
 
 ## Reading Paper Content
 

skills/research/ml-paper-writing/references/citation-workflow.md

@@ -215,6 +215,7 @@ def generate_citation_key(bibtex: str) -> str:
 
 ### Complete Citation Manager Class
 
+{% raw %}
 ```python
 """
 Citation Manager - Verified citation workflow for ML papers.
@@ -377,6 +378,7 @@ if __name__ == "__main__":
     if bibtex:
         print(bibtex)
 ```
+{% endraw %}
 
 ### Quick Functions