MB678 is complete.

What started as a large, historically grown Mediabot::Partyline module has now been decomposed into explicit architectural responsibilities without changing the external command surface, operator workflow, runtime protocol, or security model.

The final closure commit is:

Version : 3.4dev-20260822_050334
Commit  : 74bcfef
Branch  : master

🏰 Close the Partyline Chambers and Leave Only the Great Hall

The final parent module is now:

Mediabot/Partyline.pm : 295 lines

It contains exactly five core implementations:

new
get_port
_runtime_status_path
_runtime_status_payload
_write_runtime_status

And, critically:

Physical _cmd_* implementations in Partyline.pm : 0

That is the real completion criterion of MB678.

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🏚️ Where we started

Before MB678, Mediabot/Partyline.pm had grown into a large multi-responsibility module:

6976 lines

It mixed together:

TCP transport
DCC handling
sessions
authentication
command dispatch
operator commands
IRC control
runtime diagnostics
scheduler controls
AI commands
moderation
anti-flood controls
history and visibility commands
privileged eval / die controls
runtime-status export

The goal was never merely to reduce the line count.

The goal was:

same Partyline protocol
same commands
same historical method surface
same runtime behaviour
same security invariants
clear ownership of responsibilities

---

🧩 The final Partyline architecture

After MB678:

Mediabot/Partyline.pm             :  295 lines
Mediabot/Partyline/Commands.pm    : 4529 lines
Mediabot/Partyline/Dispatcher.pm  :  407 lines
Mediabot/Partyline/SessionAuth.pm :  676 lines
Mediabot/Partyline/Transport.pm   : 1013 lines
Mediabot/Partyline/Privileged.pm  :  388 lines

Responsibilities are now explicit.

Mediabot::Partyline

The final parent owns only the legitimate Partyline core:

object construction
Partyline port access
runtime-status path
runtime-status payload generation
runtime-status atomic publication
historical facade/import surface

No Partyline command is physically implemented there anymore.

---

🚂 Mediabot::Partyline::Transport

Owns:

TCP listener
DCC transport
stream handling
line/input framing
transport limits
socket-level errors
session transport bootstrap

The final closure also moved the bytes dependency to this module because this is where bytes::length() is actually used.

---

🔐 Mediabot::Partyline::SessionAuth

Owns:

session lifecycle
authentication
login throttling
timeouts
reverse DNS
session state
broadcast/session helpers

---

🧭 Mediabot::Partyline::Dispatcher

Owns:

input dispatch
command routing
historical command entry path

This preserves the external routing model while making the routing responsibility explicit.

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🧰 Mediabot::Partyline::Commands

Owns the ordinary Partyline command surface, including the successive families extracted during MB678:

plugin / ScriptDryRun
core operator/session commands
scheduler / operational commands
channel/network visibility
reminders / seen
karma
configuration reload
network statistics
IRC control/lifecycle
AI commands
runtime diagnostics
channel moderation
anti-flood/cooldown
remaining standard commands

The module is intentionally the command implementation layer.

---

🔒 Mediabot::Partyline::Privileged

Owns the two privileged controls:

_cmd_eval
_cmd_die

These were deliberately kept separate from ordinary commands because their risk profile is fundamentally different.

_cmd_eval includes guarded code execution plus watchdog/fork/reaping behaviour.

_cmd_die controls process termination.

Their historical surface remains available through Mediabot::Partyline.

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🧙 MB678 round history

The complete extraction sequence was:

I     Transport                         25949c5
II    Session/Auth                      a81729b
III   Dispatcher                        ff633dc
IV-A  Plugin / ScriptDryRun             9914aa8
IV-B  Core operator/session             1c34240
IV-C  Scheduler / operational           a28388b
IV-D  Channel/network visibility        5f48853
IV-E  Reminder / seen                   eed64c3
IV-F  Karma                             595185a
IV-G  Configuration reload              d689416
IV-H  Network statistics                702bcd6
IV-I  IRC control/lifecycle             fad3dd3
IV-J  Claude/AI                         e55b30b
IV-K  Runtime diagnostics               970f00b
IV-L  Channel moderation/control        ce059f7
IV-M  Anti-flood / cooldown             90c3d40
IV-N  Remaining standard commands       959e927
IV-O  Privileged controls               fd0b4d3
Final boundary closure                  74bcfef

This was intentionally incremental.

Each round moved one coherent responsibility and was validated before the next one began.

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📉 Structural evolution

The most visible metric is the parent module size:

Before MB678 : 6976 lines
After MB678  :  295 lines

Reduction:

6681 lines removed from the parent
~95.8% reduction

But the important metric is architectural:

Before:
    one parent carrying almost everything

After:
    parent = core/facade
    transport = Transport
    sessions/auth = SessionAuth
    routing = Dispatcher
    commands = Commands
    privileged process controls = Privileged

The code did not disappear.

The ownership became understandable.

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🧪 Contract strategy

A large part of the work involved preserving historical behaviour while correcting tests that assumed physical source location.

A method such as:

Mediabot::Partyline->_cmd_status

may still be publicly callable through Mediabot::Partyline while its implementation physically lives in:

Mediabot/Partyline/Commands.pm

That distinction became an explicit test principle during MB678:

API ownership != physical source-file ownership

Whenever an old source contract failed solely because a method moved, the contract was updated rather than the product being bent back toward the old monolith.

---

🧱 Final boundary contract

The closure introduced:

t/cases/881_mb678_partyline_boundary_closure.t

Its job is to lock the final architecture.

Among other things, the closure verifies that:

Partyline.pm contains only the intended core implementations
no _cmd_* implementation remains in the parent
module ownership is explicit
imported historical symbols have a single real owner
stale extraction tombstones are gone
the parent no longer carries dependencies belonging to extracted modules

The final MB678 Partyline contract chain:

862 -> 881

passed:

PASSED : 964/964  (5s)

---

⚡ Fast validation

The final fast lane after boundary closure:

perl t/test_commands.pl --fast --progress

Result:

Selected: 323 of 764 discovered test file(s)

[====================] 100% [323/323 files | 5982 tests]

PASSED : 5982/5982  (64s)

---

🔌 Real runtime validation

After the final boundary cleanup, the development instance restarted successfully:

mediabot@dev : active

Partyline remained listening on:

0.0.0.0:23456

The real TCP smoke path returned:

Mediabot Partyline
Please enter your nickname.
Enter your password.

Result:

RC_SMOKE=0

The journal showed:

OK: no obvious runtime error

---

🛡️ Security audit

The final security audit remained fully green:

RC_AUDIT=0

Verdict: GO — all 11 security invariants hold.

This was especially important because MB678 moved:

authentication/session code
anti-flood controls
privileged eval/die controls
transport handling

The architecture changed significantly while the audited security properties remained intact.

---

🏰 Final full regression suite

The final full suite after the closure cleanup:

perl t/test_commands.pl --progress

Result:

[====================] 100% [764/764 files | 15371 tests]

PASSED : 15371/15371  (211s)

That is the final MB678 regression reference.

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🧹 Final boundary cleanup

The last commit did not extract another command family.

Instead, it cleaned up the scaffolding left by the refactor:

Partyline.pm : 440 -> 295 lines
subs         : 5 -> 5
commands     : unchanged
routing      : unchanged
runtime      : unchanged

It removed stale historical imports and extraction tombstones.

It also moved:

use bytes ();

to:

Mediabot::Partyline::Transport

because that module is the real owner of the bytes::length() usage.

This is the difference between merely splitting files and actually completing an architectural refactor.

---

📦 Final closure commit

Version : 3.4dev-20260822_050334
Commit  : 74bcfef

🏰 Close the Partyline Chambers and Leave Only the Great Hall

Commit summary:

4 files changed
128 insertions
173 deletions

New test:

t/cases/881_mb678_partyline_boundary_closure.t

The commit was successfully pushed to GitHub.

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🏁 MB678 status

STATUS: COMPLETE

Completion criteria:

[OK] transport separated
[OK] sessions/auth separated
[OK] dispatcher separated
[OK] ordinary commands separated
[OK] privileged controls separated
[OK] historical Partyline surface preserved
[OK] parent reduced to legitimate core
[OK] no _cmd_* implementation remains in parent
[OK] final boundary contract added
[OK] runtime validation passed
[OK] security audit passed
[OK] fast suite passed
[OK] full suite passed
[OK] closure commit pushed

No further Partyline extraction is justified under MB678.

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🧭 What comes next

MB678 was a large structural project, not the final step toward 3.5.

The next work should return to the broader roadmap:

1. remaining update / observability work
2. architecture/documentation consolidation
3. full 3.5 readiness audit
4. stable 3.5 only after explicit GO

The historical update/observability work must receive a new number because MB679 is already the test-runner progress feature.

The next phase should therefore avoid immediately starting another major refactor.

The system now needs consolidation, operational visibility, documentation alignment, and readiness validation.

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🏰 The chambers are no longer piled into one room. The Great Hall remains — small, central, and finally worthy of its name.