docs: fix Microsoft.Foreign hits (e.g./i.e. -> for example/that is)

Substitutes 'for example' for 'e.g.' and 'that is' for 'i.e.' per
Microsoft style, with no comma after the replacement -- this repo
never puts a comma after e.g./i.e. either, so the substituted phrase
matches that house style instead of vale's literal 'for example,'
suggestion.

Covers all 77 real hits (72 from the initial vale pass + 5 more of the
same pattern found on a follow-up vale run). None of the flagged
instances were sentence-initial, so there's no capitalization concern
here.

Verified via a fresh vale run: 0 remaining Microsoft.Foreign hits.
Full accounting in /agents/iris/state/haiku-batches/foreign-report.md.

docs/tools/matrix.md

@@ -22,7 +22,7 @@ room you haven't read yet.
   `user_id` and return its room id **without sending anything**.
   Use the returned id with room-based tools (`send_message`,
   `send_file`, …) to deliver into a DM when `send_dm`'s body
-  parameter is inconvenient (e.g. for file attachments)
+  parameter is inconvenient (for example for file attachments)
 - `send_reply(room, event_id, body)` — threaded reply to a specific
   event
 - `send_reaction(room, event_id, key)` — react to a message with an
@@ -70,7 +70,7 @@ room you haven't read yet.
 ## Multiple accounts
 
 `hyperhive.matrixAccounts` (declared in `agent.nix`) gives an agent
-*additional* matrix identities beyond the hive-internal one — e.g. an
+*additional* matrix identities beyond the hive-internal one — for example an
 external-facing account alongside the internal one. Each entry is
 keyed by account name and specifies `tokenFile` (bearer token,
 provisioned out-of-band; basename must start with `matrix-token`),