docs(6210): acceptance sweep — src, scripts and frontend leftovers described in the present tense

The acceptance greps found what the per-area passes missed:

- src/scribe: "Phase 7/8" removal notes in projects, settings and
  user_profile; a paragraph promising an auto-summary side effect that no
  longer exists; user_profile's claim that "upcoming MCP profile tools" read
  the profile, which nothing does; an instance count and instance rule
  titles in plugin_context; "MILESTONE 323 DECIDED" in rulebooks.
- scripts/: check_plugin's header and inline comments were a history of
  the incidents behind each guard, with issue numbers in two failure
  messages; check_dangling_styles named this app's classes as its examples;
  check_design_tokens, measure_duplication and mint_plugin_version cited
  issues and checklists.
- frontend/src: forty-odd comments with four-digit issue numbers that the
  earlier frontend scan filtered out as hex colours, plus "used to" and
  "Phase N" notes.

Kept: illustrative ids (`#4181` as a bare-id example, `PR #198`), migration
Create Date headers and one migration's dated data floor, and the plugin
skills' worked examples of how to cite a record.

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

scripts/check_dangling_styles.py

@@ -8,13 +8,13 @@ like. Three ways it goes wrong, all of them silent:
 
   1. A rule is deleted and its `:hover` / modifier survives. The selector still
      exists, so nothing reads as unused, but the element renders with no base
-     styling at all. `.btn-workspace:hover` outlived `.btn-workspace` and a
-     router-link rendered as raw browser blue for days.
+     styling at all — `.btn:hover` outliving `.btn` leaves a link in raw
+     browser blue.
 
   2. The parent's layout rule is deleted while the children keep theirs.
-     `.milestone-header` was a flex row; its children still declare `flex: 1`
-     and `flex-shrink: 0`. Without the parent they stack vertically, and a
-     milestone that was one line becomes five. Nothing errors — the page just
+     A header that is a flex row loses its rule; its children still declare
+     `flex: 1` and `flex-shrink: 0`. Without the parent they stack vertically,
+     and a row that was one line becomes five. Nothing errors — the page just
      wastes space, which reads as a design decision.
 
   3. A rule is removed from a comma-separated group, leaving `.a,` dangling in
@@ -35,9 +35,8 @@ Descendant selectors count as a base — `.panel .row {}` styles `.row` — beca
 from the element's side there is no difference. Only the LAST compound of a
 selector is what it styles, and a compound's whole class SET is what it
 requires: `.pane.empty` and `td.num` are base rules for the element carrying
-those classes, not modifiers. Reading them as modifiers cost this check four
-false reports on its first run, and a check with false reports is one that gets
-skimmed.
+those classes, not modifiers. Reading them as modifiers produces false
+reports, and a check with false reports is one that gets skimmed.
 
 REPORT, NOT FAIL. Bare wrappers with no styling of their own are legitimate,
 so this cannot be a gate without a suppression mechanism nobody would maintain.
@@ -46,11 +45,10 @@ say so in a comment beside its descendant rules — the remaining reports here
 all carry one, so a new entry means something changed.
 
 KNOWN BLIND SPOT: a class with NO rule anywhere is invisible to this, because
-it cannot be told from a semantic-only hook. `.systems-list` had lost its
-entire rule and was rendering with browser bullets; it was found by reading the
-file next to a class that WAS half-styled, not by this check.
+it cannot be told from a semantic-only hook. A list whose entire rule is gone
+renders with browser bullets, and only reading the file finds it.
 
-INSTANCE-AGNOSTIC (rule #115). Nothing here knows a class name, a component, or
+INSTANCE-AGNOSTIC. Nothing here knows a class name, a component, or
 a convention; point it at any Vue tree.
 """
 from __future__ import annotations