Trim controller.py prose, pass 2: 3723 → 3186 (−537)

[bdraco]

What does this implement/fix?

Pass 1 (#630) cut method-level docstrings but left the inline
# explain what this line does paragraphs intact — which were
the actual wall-of-text problem. This pass strips those per
CLAUDE.md's "don't explain WHAT the code does, since
well-named identifiers already do that" rule.

controller.py: 3723 → 3186 lines (−537).
Prose-to-code ratio: ~1.4:1 → ~1:1 (was ~2:1 in the
pre-trim original).

Concretely

• __init__: attribute-explainer comments collapsed to
  one or two lines each — the well-named attributes already
  say what each holds. 208 → 110 lines.
• start: lost the 6-8 line preludes before every block.
  183 → 78 lines.
• stop: lost the per-drain rationale paragraphs that
  the _drain_tasks helper already encodes. 99 → 44 lines.
• request_pair: dropped the "APPROVED here means…",
  "sweep stale entry…", "re-pair against same pin…" preludes
  before each near-self-explanatory block. 140 → 97 lines.
• unpair: lost the per-clear-call rationale
  paragraphs. 89 → 24 lines.
• _apply_pair_status_result: lost the inline preludes
  on each terminal branch. 117 → 88 lines.
• record_pair_request: lost the receiver-side branch
  explainers + the 11-line PENDING-entry refresh
  explanation. 106 → 78 lines.
• submit_job / register_peer_link_session /
  set_settings / rotate_identity / set_pairing_window
  / _run_cleanup_loop: similarly trimmed.
• Module-level constant explainers (the 8-line
  cleanup-sweep cadence comment, the 6-line debounce-window
  comment, the 10-line resolve-timeout comment, etc.)
  reduced to one or two lines each.

What was kept

The WHY-style notes per CLAUDE.md:

• Post-fix bug references (e.g. the Route firmware/install through pick_build_path + REMOTE upload chain (7a-3) #568 cold-connect
  regression in register_peer_link_session).
• Hidden invariants ("fire AFTER the dict insert so
  subscriber lookups see the just-registered session").
• Surprising orderings ("snapshot to a list before
  iterating — each terminate mutates the dict").
• Non-obvious type-coercion gotchas (the bool-subclass-of-int
  caveat on cleanup_ttl_seconds).
• Security-defense rationale (the
  same-dashboard_id-different-pubkey refusal in
  record_pair_request).

Behaviour preservation

No code lines changed; only comment and docstring lines
removed. All 3117 tests pass.

Related issue or feature (if applicable):

• Follow-up to Trim controller.py prose: 4594 → 3723 lines (−871) #630.

Types of changes

• Bugfix (non-breaking change which fixes an issue) — bugfix
• New feature (non-breaking change which adds functionality) — new-feature
• Enhancement to an existing feature — enhancement
• Breaking change (fix or feature that would cause existing functionality to not work as expected) — breaking-change
• Refactor (no behaviour change) — refactor
• Documentation only — docs
• Maintenance / chore — maintenance
• CI / workflow change — ci
• Dependencies bump — dependencies

Frontend coordination

• No frontend change needed
• Companion frontend PR: esphome/device-builder-dashboard-frontend#

Checklist

• The code change is tested and works locally.
• Pre-commit hooks pass (ruff, codespell, yaml/json/python checks).
• Tests have been added or updated under tests/ where applicable.
• components.json has not been hand-edited (regenerate via script/sync_components.py if a sync is needed).
• Architecture-level changes are reflected in docs/ARCHITECTURE.md and/or docs/API.md.

[codspeed-hq]

Merging this PR will not alter performance

✅ 12 untouched benchmarks

---

_{Comparing trim-controller-prose-pass2 (aed5b62) with main (b946b69)}

[Copilot]

Pull request overview

This PR further reduces the “wall-of-text” in RemoteBuildController by trimming inline explanatory prose and condensing docstrings, aligning the file more closely with the comment style guidance in CLAUDE.md (focus on why and invariants vs. narrating what the code does).

Changes:

• Collapsed/removed large inline comment blocks and constant explainers across controller.py.
• Condensed several lifecycle and remote-build flow docstrings to shorter summaries while keeping key invariants/security rationale notes.
• Left runtime logic unchanged (documentation-only refactor).

[codecov-commenter]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 99.21%. Comparing base (b946b69) to head (aed5b62).
⚠️ Report is 1 commits behind head on main.

Additional details and impacted files

@@           Coverage Diff           @@
##             main     #633   +/-   ##
=======================================
  Coverage   99.21%   99.21%           
=======================================
  Files          90       90           
  Lines       10757    10757           
=======================================
  Hits        10673    10673           
  Misses         84       84           

Flag	Coverage Δ
py3.12	99.19% <ø> (ø)
py3.14	99.21% <ø> (ø)

Flags with carried forward coverage won't be shown. Click here to find out more.

Files with missing lines	Coverage Δ
...ice_builder/controllers/remote_build/controller.py	99.67% <ø> (ø)

🚀 New features to boost your workflow:

• ❄️ Test Analytics: Detect flaky tests, report on failures, and find test suite problems.