Address review feedback (payload handler, arch, SessionTypes, DLL_NAME validation, doc cleanup)

[prithvee07]

Description
Addresses the outstanding review feedback from dledda-r7 and h00die on rapid7#21128 ("Add Persistence Technique: Windows Port Monitor"), applied directly on top of win-port-monitor so it can be merged into that PR before it lands upstream.
Changes:
Removed the DefaultOptions block that disabled the payload handler and hardcoded windows/x64/meterpreter/reverse_tcp. Persistence modules install a payload that fires later (on Spooler restart/reboot), so the handler needs to stay up to catch that callback — disabling it defeats the module's purpose.
Removed ARCH_AARCH64 from Arch, since Metasploit doesn't yet have a meterpreter or shell payload for that architecture.
Restricted SessionTypes to meterpreter only (was ['meterpreter', 'shell']).
DLL_NAME no longer fails with Failure::BadConfig when it's missing a .dll extension — payload_name now appends .dll automatically instead.
MONITOR_NAME and DLL_NAME now default to randomized 8-character alpha strings (Rex::Text.rand_text_alpha(8)) instead of the static Hadess / persist.dll, and are marked required to match.
Documentation: restructured ## Scenarios to use ### <OS> / #### <scenario> heading levels, removed the unrelated local_exploit_suggester detour from the console transcript, fixed an escaped   HTML entity and a doubled backslash inside a code span, and updated the Options section text for the new randomized defaults. tools/dev/msftidy_docs.rb passes clean.
Related Issue: Addresses review comments on rapid7#21128
Breaking Changes
None — no datastore option names were removed, only default values and required-ness changed (MONITOR_NAME/DLL_NAME defaults are now randomized instead of static, and both are now required instead of optional).
Reviewer Notes
This is scoped to exactly the changes requested in review — no unrelated module edits. Diff touches only modules/exploits/windows/persistence/port_monitor.rb and its documentation file.
Verification Steps

[ ] ruby -c modules/exploits/windows/persistence/port_monitor.rb — confirms syntax (already run, passes).

[ ] ruby tools/dev/msftidy_docs.rb documentation/modules/exploit/windows/persistence/port_monitor.md — confirms doc formatting (already run, passes clean).

[ ] use exploit/windows/persistence/port_monitor; show options — confirm MONITOR_NAME/DLL_NAME now show randomized defaults and Required: yes.

[ ] set DLL_NAME foo (no extension) then run against a live/lab target — confirm it installs as foo.dll instead of erroring out.

[ ] Full end-to-end run against a Windows target: install persistence, restart/reboot, confirm the handler receives a new meterpreter session (this step still needs to be performed and recorded — see the <!-- TODO --> left in the doc's transcript).
Test Evidence
ruby -c and msftidy_docs.rb both pass clean on the changed files (see Verification Steps 1–2). I have not run this against a live Windows/Print Spooler target — steps 3–5 above still need real console output from testing against a lab target before this should be considered fully verified.
Environment
Field Details
Operating System (fill in your dev OS)
Target Software/Hardware Windows Print Spooler — (fill in Windows version(s) tested)
Docker Image / Vagrant Setup (fill in if used, otherwise remove this row)
AI Usage Disclosure
Claude (Anthropic) was used to identify and implement the fixes requested in review: removing the payload-handler/meterpreter defaults, dropping aarch64 support, restricting SessionTypes, the DLL_NAME auto-extension change, randomized option defaults, and the documentation restructuring/cleanup. Per CONTRIBUTING.md, this code has been syntax- and lint-checked but has not yet been exercised against a live target — see Test Evidence above.
Pre-Submission Checklist
[x] No sensitive information (IP addresses, credentials, API keys, hashes) in code or documentation
[ ] Tested on the target environment specified in the Environment section above
[ ] Included RSpec tests for library changes (encouraged for lib/ changes — n/a, no lib/ changes here)
[ ] Read the CONTRIBUTING.md and module acceptance guidelines