Issue 320 and ADR 0253: a condition says itself to the operator in plain words

The operator could not read the mesh's notifications: they were the summary meant
for an agent, with ids, commits, keys and verbs, in UTC. The condition now carries
a headline, an explanation and a resolved line beside its summary.

03-DESIGN/01-to-be/45-a-core-that-cannot-fail-silently.md

@@ -4,6 +4,7 @@ status: in-progress
 code: [mesh-controller, mesh-host, mesh-tools, mesh-catalog, mesh-sdk, mesh-lab]
 updated: 2026-10-08
 decisions:
+  - 02-DECISIONS/0253-a-condition-says-itself-to-the-operator-in-plain-words-beside-its-summary.md
   - 02-DECISIONS/0240-a-module-says-how-it-is-healthy-and-the-node-engine-judges-it.md
   - 02-DECISIONS/0239-a-delivery-is-owned-by-the-mesh-delivery-module-and-runs-from-commit-to-delivered.md
   - 02-DECISIONS/0238-a-commit-is-the-build-at-hand-one-commit-one-change-plan-checked-off-the-trunk-and-published-only-on-it.md
@@ -126,7 +127,8 @@ cleared on the first that does not. Designed in [to-be 48](48-a-module-says-how-
 | kind | the condition kind, from the signals table, the probe registry or an event kind |
 | subject | scope, id, and the machine it concerns when there is one |
 | severity | `urgent` (needs the operator now) or `warning` (when they can) — two levels, no more |
-| summary | one line in the mesh's words |
+| summary | one line in the mesh's words, for whoever looks closer: it may name plans, commits and verbs |
+| headline, explanation, resolved | what the operator reads, in plain words (ADR 0253): a few words naming the thing and what is wrong; one or two sentences on what happened, what it means and whether to act; the line said when it clears |
 | evidence | the newest observations, at most ten, each with its time |
 | source | the signals-table row, probe or event that raised it |
 | raised, last observed | times; and how many observations since raised |
@@ -135,6 +137,17 @@ cleared on the first that does not. Designed in [to-be 48](48-a-module-says-how-
 | silenced | until when, by whom, why — empty when not silenced |
 | epoch | the controller lease epoch that last wrote it |
 
+*Added 2026-10-08, [ADR 0253](../../02-DECISIONS/0253-a-condition-says-itself-to-the-operator-in-plain-words-beside-its-summary.md):*
+**a condition says itself to the operator in plain words, beside its summary.** The headline, explanation
+and resolved line are made where the condition is made: by the producer when it knows more than the
+subject (a walk's modules, a failed unit's name, a hand-act's cause), otherwise by the wording registered
+for the kind, otherwise from the scope, which is reported. All three are held to the plain rule when the
+controller takes an observation: no hash, numbered id, dotted name, duration in code, clock time, flag,
+markup or line break, and the content rule besides. Words that break the rule are replaced by the scope's
+words, never refused. A condition a healer gave up on says in its explanation that it needs the operator.
+Checked by the plain rule's test and by a lint over every condition the controller's suite raises, which
+fails a kind without words.
+
 **The life of one:**
 
 ```
@@ -284,6 +297,12 @@ section; to-be 46 §13 builds what follows from it.
   secrets, and this seat's holder becomes the router (to-be 46 §2, §3, §8).
 - **A message** is: the condition's key, its subject (a machine's role, a module, a plan), kind,
   severity, the one-line summary, since when, and the verb that shows more. **Deduplicated by the key.**
+  *Amended 2026-10-08, [ADR 0253](../../02-DECISIONS/0253-a-condition-says-itself-to-the-operator-in-plain-words-beside-its-summary.md):*
+  a message reads in one glance. Its title is the condition's headline, with "Urgent:", "Still open:" or
+  "Now urgent:" before it where that applies. Its body is the explanation and since when, in the
+  operator's time zone (the messenger's setting `time-zone`). It carries no key, id, commit, verb or
+  markup: those stay in `conditions` and in the holder's history. A clearance is one line, the resolved
+  line and how long it was open. A digest lists titles. Still deduplicated by the key.
 - **When:** on `condition-raised`; once more if still open after 1 hour (urgent) or 12 hours
   (warning); on `condition-cleared`, by editing the first message where the channel can. A silenced
   condition sends nothing. Urgent goes to both channels; warning to the desktop notifier when the