Code Clean

Two passes over termio's Swift: dead code (symbols nothing reaches) and over-long comments (prose that outgrew what it explains). Both end in a build. Neither is a refactor.

This is not a generic AI-slop sweep. Run one on this repo and it finds nothing: a 2026-08 survey of all 69k tracked Swift lines turned up 1 TODO (a false match on an mktemp template), 0 commented-out code blocks, and 1 deliberate debug print. Don't spend the pass hunting those. The bloat here is shaped differently, and §2 is where it lives.

Scope

Default to the current branch's diff against origin/main. A whole-tree pass is a standing request only — say so, and expect it to take real time.

Never touch:

• Sources/termio/Editor/Highlightr/ — vendored; upstream API surface is kept intact on purpose (AGENTS.md).
• Anything under skills/ recorded in skills-lock.json — re-pull from upstream instead of hand-editing.
• ios/build/, ios/build-sim/ — Xcode artifacts, not tracked source. They hold ~100k lines of SPM checkouts that will swamp any tree-wide grep. Scope greps with git ls-files, never bare find ios.

1. Dead code

periphery scan --targets termio (SPM; no config file needed). It is installed at /opt/homebrew/bin/periphery.

Roughly three of every four hits are false. Four shapes account for nearly all of them — clear each before deleting anything:

1. Retain-holders. private var toolbarDelegate / menuBar / hookListener / linkClickMonitor / scanTask / stream / source / window. Flagged assignOnlyProperty, but holding the reference is the job — drop the property and the object deallocates and the feature dies. App.swift says so in comments ("must be retained").
2. Equatable / Hashable key-struct fields. Read only through the synthesized == / hash(into:), which periphery cannot see. BranchModel's GitState spells out why its field exists: so a same-HEAD refresh is recognized as a no-op.
3. @objc selector-target sender: parameters. The AppKit selector signature requires them.
4. Vendored code. See Scope.

Two more that are unused and must stay:

• Documented extension points — the IssueProvider protocol is unused as a type but is the seam for Linear (docs/design/issue-tracker-integration.md).
• Persisted fields — Session.createdAt is unread but lives in the state file. Deleting it is a schema change, not a cleanup.

Real finds cluster in fetch-and-cache paths whose views were never wired and utilities orphaned when their UI was removed. Before deleting, grep the symbol across Sources, Shared, ios/Sources, Tests, and scripts/. If only a test references it, the test is holding a corpse upright — delete both.

2. Over-long comments

The repo's actual bloat. Of 3,293 doc-comment blocks in Sources + Shared, 81% are 1–5 lines and healthy. The tail is not: 636 blocks run 6+ lines, 151 run 12+, and the longest is 44 lines — a design doc wearing a function header.

Find them:

git ls-files 'Sources/*.swift' 'Shared/*.swift' 'ios/Sources/*.swift' | xargs awk '
  /^[[:space:]]*\/\/\//{if(n==0)start=FNR; n++; next}
  {if(n>=12){print n" "FILENAME":"start}; n=0}
  END{if(n>=12)print n" "FILENAME":"start}' | sort -rn

The test that matters

AGENTS.md says comments explain why, not what. These comments already do — that is exactly the trap. Length is not the defect; misfiling is. A 20-line block is wrong not because it is long but because a field's doc comment is the wrong home for a design argument.

Sort every long block into three piles:

• Keep, verbatim. A foot-gun, an invariant, or a past bug that will be reintroduced without it. Workspace.isAutoCreated's note on why Bool? has three states, not two, is load-bearing: collapsing it to false is what made an earlier version wrong. Length is irrelevant here. Leave it.
• Move to docs/design/, leave a one-line pointer. Architecture, alternatives considered, upstream asks, competitor comparisons. The 44-line block on makeStatusTap is three paragraphs of model plus a caveat with an upstream ask — that is a design doc. Use the doc skill to create or extend it, then leave /// … see docs/design/<file>.md. Move, never delete.
• Cut. Restating the signature, narrating the body line by line, hedging ("this should probably"), and prose that repeats the paragraph above it.

Tautological one-liners

~130 docs open /// Whether the … and many just respell the property name:

/// Whether the "Projects" section is folded shut.
var isProjectsCollapsed: Bool

Delete that. But /// Whether the machine answered at all. false is what turns every agent row … earns its line — it says what the value causes. Read each one; do not pattern-match the opener.

Ceilings, once a block is in the "cut" pile

One line is the target. Three is the ceiling for a field or inline comment, five for a type or function. A block that cannot fit belongs in docs/design/.

Leave alone

• // MARK: — all 602 of them. They are navigation, not narration, and they are spread thin (12 in the heaviest file). AGENTS.md's ban on "organizational comments" is about prose headers that summarize what the next block does.
• Comments on code this branch did not touch, in a diff-scoped run.
• An outdated comment: fix it, don't reword it to match wrong code. If the code is what's wrong, report that separately — it is a bug, not a comment.

3. Verify

swift build          # required, every time
swift test           # if anything under a covered unit moved

Covered units: split-tree layout, OSC parsing, stall probing, Markdown/HTML rendering, git service, editor text, install feedback.

A comment pass that changes no code still needs swift build — a deleted line inside a multi-line string or a stray /// before an attribute breaks the parse.

Report

Per file: what was cut, what moved to docs/design/, and what was flagged but kept and why. Name the periphery hits you rejected and which of the four shapes each was — that list is how the next run gets faster.

Do not report a line count as the result. "Cut 400 lines" says nothing about whether the right 400 went.