board: /tasks confirms a candidate into an open task (V-511)

The candidate row is now an intake form, not a button. Confirming asks for a
definition of done and refuses without one, takes an optional blocked-on name,
and carries the date and the importance through.

The blocked-on is a name in the form and a canonical nexus id in the store.
promoteCandidate resolves it over the new ipc.ResolveEntity seam and stops the
confirmation on an ambiguous or unplaceable name rather than picking.

A date set here books a reminder for 09:00 that morning. That is the only
unprompted delivery the persona allows, because the owner set the date himself.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01SoL7EBdYC5Mhz3DJd49GJy

cmd/mavweb/tasks.html

@@ -37,16 +37,27 @@
 <section class=card>
 <h2 class=card-title>found, not confirmed <span class=badge>{{len .Candidates}}</span></h2>
 <div class=hint>maven derived these from something she read. nothing counts as your work until you confirm it.</div>
+<div class=hint>confirming asks for a definition of done: what has to be true for this to be finished. a task without one can never leave the board. a date here also books a reminder that morning.</div>
 <div class=scroll><table>
-<tr><th>task</th><th>where from</th><th>due</th><th>captured</th><th></th><th></th></tr>
+<tr><th>task</th><th>where from</th><th>captured</th><th>confirm</th><th></th></tr>
 {{range .Candidates}}<tr>
 <td class=text-max>{{.Text}}</td>
 <td class=hint>{{.Source}}{{if .Evidence}} — {{.Evidence}}{{end}}</td>
-<td>{{.Due}}</td>
 <td class=muted>{{.Created}}</td>
 <td><form method=post action=/tasks class=inline-form>
 <input type=hidden name=id value="{{.ID}}">
-<input type=hidden name=action value=confirm>
+<input type=hidden name=action value=promote>
+<input type=hidden name=text value="{{.Text}}">
+<input type=text name=done_when placeholder="готово, когда…" size=26 required>
+<!-- A name, not an id. It is resolved against nexus before anything is
+     stored, and a name nexus cannot place stops the confirmation. -->
+<input type=text name=blocked_on placeholder="ждёт кого-то" size=14>
+<input type=date name=due value="{{.DueValue}}" title="due date">
+<select name=weight title=importance>
+<option value=0 {{if eq .Weight 0}}selected{{end}}>normal</option>
+<option value=2 {{if eq .Weight 2}}selected{{end}}>важно</option>
+<option value=3 {{if eq .Weight 3}}selected{{end}}>срочно</option>
+</select>
 <button class=btn>confirm</button></form></td>
 <td><form method=post action=/tasks class=inline-form>
 <input type=hidden name=id value="{{.ID}}">