Adds Notes on three stale ADR sentences

[johnnyt]

Appends one dated foot Note to each of ADR-0005, ADR-0006 and ADR-0007, meeting a stale sentence in each. Docs-only: no line above any Note changes (git diff origin/main -- docs/adr/ shows additions only), no status word flips, no changelog fragment, no lib/ change.

Beads: ece-tdw0, with ece-few folded in (both are ADR-0005 foot-Note fixes; the one ADR-0005 Note serves both).

What each Note says

• ADR-0007. The Context's "Today a host writes it by hand, as the Google Cloud KMS guide's shred step does" was true when the record was written and is not on main: the guide's Step 6 deletes the row with Encryptor.Ecto.KeyStore.shred/3 and warns against a hand-written delete_all. The guide changed in 4e9deb2, an ancestor of v0.6.0.
• ADR-0006. The acceptance Note quoted one owner-noun sentence of the key-store generator; the two key-store generators carry four. The Note lists each with its anchor and reads it, as the acceptance Note read the first, as text about the kept tenant_ref column and its index (decision 3, W1 and W2). It also names the quotation of encryptor's P3 step 2 in the comment above recheck/5, added after the acceptance.
• ADR-0005. Section 1 reads Amendment A's A4 claims that name 0.4.1 ("shipped at the pinned 0.4.1", "not fully met through the 0.4.1 public surface") at the 0.5.0 pin. Section 2 gives three readings of the 2026-09-14 Note: its section 2's counting advice is advice, not a rule; its "off by ... a counting scope" cite is under-scoped rather than off; its one-line rendering of the crypto_key_name head drops the trailing comma of a two-line head. Section 3 states how a count in this file is read: scoped to the lines and SHA it names.

Direction check (in-turn review)

Every claim was checked against encryptor_ecto main and encryptor tags before the PR opened. ADR-0007: the guide at the record's own commit taught MyApp.Repo.delete_all(; the guide on main calls shred/3 and carries the "takes no lock, waits for no drain and leaves no record" sentence; git merge-base --is-ancestor 4e9deb2 v0.6.0 succeeds. ADR-0006: grep -n tenant over the two generators, excluding tenant_ref, gives exactly the four lines the table anchors (:9, :69, :134 of the key-store generator, :72 of the shape generator); git diff ad08848 HEAD over both generators is empty; lib/encryptor/ecto/key_store.ex:717 sits in the comment above defp recheck, came in with aa78d82, and its quoted words match step 2 of P3 in encryptor's docs/adr/0005-rotation-and-crypto-shred.md. ADR-0005: mix.exs pins {:encryptor, "== 0.5.0"}; at encryptor v0.5.0 (9ad74e2) Encryptor.Provider.GcpKms has public init/1 and decryption_keys/2, and the private unwrap/3's {:error, _failure} arm answers {:key_unavailable, selector}; at v0.4.1 (4c8fbe9) crypto_key_name's head is gcp_kms.ex:376, ending in a comma, with do: on :377, and at v0.5.0 it is :379 in the same form; the three quoted phrases of the 2026-09-14 Note are verbatim. The ADR-0005 Note names none of the strings the earlier counts count, so it moves none of them. Tier: gate (docs-only, no contract surface, under the size threshold).

Provenance

• The ADR-0005 Note serves both beads: section 1 for ece-tdw0, sections 2 and 3 for ece-few. ece-few's convention item goes in the same Note rather than in docs/adr/README.md.
• Gate: not run. This repository's CLAUDE.md says a change touching no Elixir code has no gate to run and may commit on review of the diff alone.
• Rebased onto main after a sibling merge (e3581e6) that touches none of the files this PR changes or cites.