capabilities: read a plugin's where they live, stop copying them in

Four publishers copied a plugin's affordances, notifications and skills into
capabilities/ at install. That directory is meant to be forked — core's work
plus the owner's — so a fork accumulated files it did not author with nothing on
disk saying which, and there was no good answer: commit them and carry another
plugin's work, leave them and git status stays dirty.

Copying was also wrong in two ways unrelated to git. A copy goes stale, because
plugins:update pulls the plugin's directory and the copy keeps describing the
old version. And a copy survived plugins:disable, so a disabled plugin's skill
stayed in the agent's index — off, and still being announced.

Now the loaders take a list of roots: the owner's store, plus each installed AND
enabled plugin's own directory. capability-sources.ts resolves that list. No
namespace is needed to keep them apart, because separate directories do it
structurally rather than by convention.

The owner's own win a skill name collision — their root is first and the merge
keeps the first of each id — so a plugin cannot take over a name already in use.
Affordances are deliberately NOT de-duplicated: several can be true at once.

Notifications needed more than a root list, and it would have failed silently.
Their codes were derived from the COPY'S PATH, <publisher>/<appName>/file.yaml.
Read in place the path is just notifications/catalogue.yaml and carries no
identity, so every plugin code would have vanished with nothing raised.
loadPluginEntries takes the identity from the manifest instead, which is better
provenance anyway — publisher and appName are validated at discovery, where a
path was only ever a directory somebody chose. A yaml key still cannot claim
another namespace, and that is pinned by test.

createSession is async now, only because resolving enabled plugins reads the
database. Once per session; its single caller already awaited.

Deletes all four publishers including api/tasks/publish.ts from earlier today,
superseded before it shipped. app-store/assets stays — images served over HTTP,
where the copy is what makes them reachable.

NOT done: tasks. That store is read-write, so reads must span sources while
writes stay in the owner's directory, and a plugin's task has to be read-only in
the UI. Next.

Two things the design predicted as orphans turned out not to be, and both were
checked before deleting rather than after. capabilities/extensions/tool-loader
is written by the platform's own bootstrap every boot, not published by a
plugin. And skills/email-db has no source to fall back on — the email plugin
ships no skills directory, so that file exists in exactly one place and was
hand-written. Neither was touched.

1422 pass, tsgo clean, officer restarts and serves.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Officer-Session: 656f5c85-e49a-4f1f-b9f3-042a04b4d043

src/servers/affordances/load.ts

@@ -1,6 +1,7 @@
 import { readdirSync, readFileSync } from 'node:fs';
 import { join } from 'node:path';
 import { OFFICER_ITEMS_DIR } from '../data-path';
+import { capabilityRoots } from '../capability-sources';
 
 // What the platform tells an agent about the surface it is speaking through.
 //
@@ -107,6 +108,21 @@ export function compileAffordances(affordances: Affordance[]): string | null {
 }
 
 /** Read and compile in one step, for callers that only want the string. */
-export function affordanceBlock(root: string = AFFORDANCES_DIR): string | null {
-  return compileAffordances(loadAffordances(root));
+/**
+ * Every affordance in force: the owner's own, plus each installed and enabled plugin's.
+ *
+ * Read in place rather than copied in — see `capability-sources.ts`. Unlike skills these are NOT
+ * de-duplicated by name: an affordance is a paragraph of guidance, several can be true at once, and two
+ * plugins describing the same surface differently is information rather than a collision.
+ */
+export function loadAffordancesAcross(roots: string[]): Affordance[] {
+  return roots.flatMap((root) => loadAffordances(root));
+}
+
+/**
+ * Read and compile in one step. Async because resolving which plugins are enabled reads the database;
+ * called once per session, which is what makes that affordable.
+ */
+export async function affordanceBlock(): Promise<string | null> {
+  return compileAffordances(loadAffordancesAcross(await capabilityRoots('affordances')));
 }