/tasks edits a task in place (V-509)

The open list carries the text, the date and the importance as an inline form
with a save button. The status is not in it: that ladder is one-way and has
its own two buttons.

The step-up gate was re-argued rather than inherited, which is what the task
asked for, and edit stays ungated. It rewrites a line on a list he reads
himself, the same blast radius drop already has here, and the store refuses
the two edits that would cost something. A collision is named ("another open
task already says this"), not merged.

A weight outside the three rungs keeps its own option in the select, or
saving an unrelated edit would silently reset it to normal.

cmd/mavweb/tasks.html

@@ -60,12 +60,27 @@
 <h2 class=card-title>open <span class=badge>{{len .Open}}</span></h2>
 <div class=hint>most pressing first — by the deadlines and the urgency you gave. nothing about a task is guessed; the only signal that is not yours is age, which lifts anything sitting here for weeks.</div>
 {{if .Open}}<div class=scroll><table>
-<tr><th>task</th><th>why</th><th>from</th><th>due</th><th>captured</th><th></th><th></th></tr>
+<tr><th>task</th><th>why</th><th>from</th><th>captured</th><th></th><th></th></tr>
 {{range .Open}}<tr>
-<td class=text-max>{{.Text}}</td>
+<!-- The text, the date and the importance are editable in place (V-509): a
+     dictated task can carry a typo, and a deadline moves. The status is not
+     here — that ladder is one-way and has its own two buttons. -->
+<td class=text-max><form method=post action=/tasks class=inline-form>
+<input type=hidden name=id value="{{.ID}}">
+<input type=hidden name=action value=edit>
+<input type=text name=text value="{{.Text}}" size=30 required>
+<input type=date name=due value="{{.DueValue}}" title="due date">
+<select name=weight title=importance>
+<!-- Any weight that is not one of the three rungs keeps its own option, or
+     saving an unrelated edit would silently reset it to normal. -->
+{{if and (ne .Weight 0) (ne .Weight 2) (ne .Weight 3)}}<option value={{.Weight}} selected>{{.Weight}}</option>{{end}}
+<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 btn-muted">save</button></form></td>
 <td class=hint>{{.Why}}</td>
 <td class=hint>{{.Source}}</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}}">