Enforce remaining docstring↔signature consistency rules (D417, DOC502, DOC201)

[dgarros]

Why

Follow-up to #1184, which adopted the Google docstring convention and turned on
the first two consistency rules (DOC102, DOC402). This issue covers the rest of
the docstring↔code accuracy rules — the high-value ones that catch docstrings
that lie about the code. They're currently parked in the ignore list in
pyproject.toml under the "Documentation rules (D and DOC)" block.

Goal: fix the violations and un-park each code so it's CI-enforced going forward.

Non-goals: the "missing docstring" presence rules (D100–D107) — tracked separately
in the Phase 2 issue.

Scope

Three rules remain parked, in ascending order of effort:

Code	Rule	Count	Notes
D417	undocumented-param	22	Mostly client.py; a documented function missing an Args entry
DOC502	docstring-extraneous-exception	31	⚠️ Known false positives for exceptions raised transitively through helpers — review case-by-case; some may warrant a per-line # noqa rather than a docstring change
DOC201	docstring-missing-returns	194	Largest; splittable per module (client, node, ctl, …)

Total ≈ 247 violations.

Approach

1. One PR for D417 (22) — smallest, concentrated in client.py.
2. One PR for DOC502 (31) — triage false positives (transitive raises) vs real
   extraneous Raises: entries; fix the real ones, # noqa: DOC502 the transitive
   ones with a short reason.
3. DOC201 (194) split across a few PRs by module to keep each reviewable.
4. Remove each code from the ignore block in pyproject.toml as its count hits zero.

Done when

• D417, DOC502, DOC201 are removed from the parked ignore list.
• uv run ruff check is green.
• uv run invoke docs-generate produces no diff (docstring edits reflected in generated docs).