docs: 1.2.0 changelog — drop pre-1.1.0 carryover entries

The 'KeydbSource owns save+update' (Added) and 'Processing-Key
decryption restored' (Fixed) entries were stale carryover from the
never-released 1.1.0-beta.1; that code shipped in v1.1.0 (zero diff in
v1.1.0..HEAD). The 1.2.0 entry now lists only the real 1.2.0 changes
(hex unification, DiscInputs version stride, MKB cap).

CHANGELOG.md

@@ -2,11 +2,6 @@
 
 ## [1.2.0] — 2026-06-28
 
-### Added
-
-- `KeydbSource` now owns keydb save + update (atomic write to the source's own
-  path); honors the caller-supplied location.
-
 ### Changed
 
 - **One hex parser across the toolchain.** Online and keydb hex inputs now parse
@@ -18,12 +13,3 @@
   at their own stride.
 - **Online MKB read cap aligned with libfreemkv (64 MiB)**, and an over-cap MKB
   is logged rather than silently truncated.
-
-### Fixed
-
-- **Processing-Key decryption restored.** A keydb Processing Key is again driven
-  through the full AACS chain — PK → Media Key (against this disc's own MKB) →
-  Volume Unique Key (with the disc Volume ID) → unit keys — so discs that ship
-  only a Processing Key decrypt again. Stored Media Keys and Volume Unique Keys
-  are still honored directly. (Cross-disc Media-Key reuse remains intentionally
-  disabled.)