Server comments describe the code to a stranger (#6221)

Rule 32 "Comments describe the product to a stranger" sweep over
src/, alembic/ and tests/. Comments and docstrings now say what the code
does and the reason as a present-tense constraint, briefly.

Removed:
- issue, task, note, rule, milestone and family-idea references
- "used to" / before-and-after narration
- quotes of decisions and incident stories from the deploying instance
- paragraph-length arguments, where a line or two carries the fact

Kept every hazard as a present-tense fact, e.g. timing oracles, the
proxy hop direction, and migrations that must stay frozen.

Also:
- Three test names lose "still"/"used to"/"pre_m304" phrasing.
- pyproject's description drops "FabledSword family".

The history these comments carried stays in Scribe and in git log.
A comment-stripping diff (Scribe snippet #6226 "codeonly.py — prove a
diff changed only comments") shows no code changed apart from the
renamed tests and the description string.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

tests/test_app.py

@@ -31,11 +31,8 @@ async def test_unknown_api_route_404s(app):
 
 # --- the version a running server reports ------------------------------------
 #
-# Note 3127 §5 removed version tags, so this string is the only answer to "which
-# build is this?" and nothing exists to contradict it when it is wrong. That makes
-# the FALLBACK the interesting case rather than the happy path: it used to be
-# `__version__`, so a server run from a checkout reported `0.2.0` — a real-looking
-# version naming no build anybody could obtain.
+# The only answer to "which build is this?", so the fallback matters most: it must
+# be "unknown", never a plausible-looking `__version__`.
 
 
 async def reported_version() -> str: