docs: cite MESHBAY_DESIGN.md and a section instead of the merged notes

The per-feature design notes were merged into docs/MESHBAY_DESIGN.md and
deleted from the tree on 2026-09-11, but ~230 comments across the three
packages still named them — usually written `docs/musicbay.md §3.2`, as
though the file were still in docs/. A reader had to know §16 existed to
resolve any of them. They now name the section directly.

Every mapping comes from §16, the concordance, which already records where
each old section landed: musicbay -> §9.8, mediacenter -> §9.7 for the
Videos app and §6.5 where the subject is derived data, photos -> §9.9,
auth-confirm -> §3.6, refactoring-search -> §9.11, invite-pairing-v1 ->
§3.4, per-node-identity-v1 -> §3.2, captcha -> §7.7, chat-sender-keys ->
§4.5, apps/refactor-groups -> §9.1–§9.4, desktop-client-v1 per section.
Bare citations of the same documents (`draft-v6 §2.11`, `§4.8`, `§3.4`)
are retargeted too: those collide with real section numbers in the design
document, so leaving them would have been worse than the named form.

Four cases the concordance does not cover, each decided rather than guessed:

  Sub-item references into documents that no longer exist — mediacenter's
  `§3.3 row 4`, `§3.4b/c`, `apps.md §3b` — name rows and sub-items §9.7 and
  §9.2 do not reproduce. The module-level citation stays; the sub-item
  pointer is dropped.

  The V-findings keep their labels but lose the dead `§10.1/` prefix.
  §13.8 lists V1–V13 as per-application open items, which is not what the
  labels mean in these comments, so pointing them at §13.8 would have been
  a false citation.

  `apps.md §5`'s virtualization requirement has no counterpart anywhere in
  the design document. The requirement is stated in the comment itself, so
  the citation is dropped rather than aimed at a section that does not say
  it.

  Comments that attributed a *sentence* to an old note — musicbay's "several
  thousand files" example, its "what got measured" note, its measured
  ~11%/~26% cover-art figures, the "original no root, whole shared tree"
  call — state the fact without attribution now. §9.8 does not contain those
  sentences and citing it for them would have been wrong.

CLAUDE.md's "a reference to a document that no longer exists" row now says
the concordance is for git history and out-of-tree material; the code cites
sections directly.

Verified: 2851 passed, 4 skipped. The 12 errors in the run are the Firefox
leg of test_sticky_header.py's browser harness, which is broken at the
browser level on this machine — headless Firefox (snap) dies with
`[GFX1-]: RenderCompositorSWGL failed mapping default framebuffer`, renders
nothing, and the probe exits `{"error": "no measurement"}` after its full
90s wait. Chrome runs the same 12 assertions in 3.2s and passes. Nothing
here can affect it: every changed line in style.css is inside a comment.
Also checked: ast.parse on every changed .py, `node --check` on every
changed .js, the /* */ balance in style.css, and that no changed line
exceeds the width its file already used.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>

1 files changed, 7 insertions, 6 deletions

diff --git a/packages/meshbay-node/src/meshbay_node/indexer/indexer.py b/packages/meshbay-node/src/meshbay_node/indexer/indexer.py
index 887d435..3fe4f3e 100644
--- a/packages/meshbay-node/src/meshbay_node/indexer/indexer.py
+++ b/packages/meshbay-node/src/meshbay_node/indexer/indexer.py
@@ -82,7 +82,8 @@ def _is_indexable(path: Path) -> bool:
 
 # Found live: a 1256-byte ".mp3" with no audio stream at all, just an ID3
 # tag — a truncated/corrupted rip, sitting between two good tracks of the
-# same album (docs/musicbay.md). A source this small claiming to be audio
+# same album (docs/MESHBAY_DESIGN.md §9.8). A source this small claiming to
+# be audio
 # is far more likely broken than real, so it is skipped before ever being
 # hashed rather than indexed and left to fail at playback time. Scoped to
 # audio only — a tiny real file of any other type is still worth indexing.
@@ -186,9 +187,8 @@ def _size_files(files: list[Path]) -> list[tuple[Path, int]]:
     executor for the same reason `_walk_root` is (its own docstring above).
     Previously a plain loop straight on the asyncio event loop thread: for a
     root with many thousands of files (a real personal library, not a
-    hypothetical — docs/musicbay.md's own "several thousand files" example)
-    that blocked the entire daemon, every WebRTC session and the admin UI
-    included, for as long as the stat() calls took — and did so *before*
+    hypothetical) that blocked the entire daemon, every WebRTC session and
+    the admin UI included, for as long as the stat() calls took — and did so *before*
     `_scan_root` had even set `progress.scanning`, so a consumer polling it
     saw "not scanning" the whole time real, blocking work was happening.
     """
@@ -673,8 +673,9 @@ class DirectoryIndexer:
 
         Entries under a root that is gone from the config are dropped — the
         operator removed it deliberately, which is not the same event as a
-        volume disappearing, and conflating the two is what §6.9 exists to
-        prevent. Roots that survive keep their entries; new ones are scanned.
+        volume disappearing, and conflating the two is what
+        docs/MESHBAY_DESIGN.md §6.2 exists to prevent. Roots that survive
+        keep their entries; new ones are scanned.
 
         The set takes effect before anything is scanned: the roots table, the
         watcher and `self.roots` all move at once. With ``wait=False`` the scan