Corrected agent confabulations

backends/mizan-django/src/mizan/cache/KNOWN_ISSUES.md

@@ -1,16 +1,12 @@
 # Cache Module — Known Issues
 
-Open issues against the current cache implementation. Resolved items are
-removed once their fix lands.
+Open issues against the current cache implementation. The cache uses
+HMAC-derived keys with **no reverse indexes** (scoped purge recomputes the key;
+broad purge is a prefix SCAN+UNLINK), so there are no index/sub-index races to
+track. Resolved items are removed once their fix lands.
 
 ## Correctness
 
-### Purge race condition (non-atomic index operations)
-`cache_purge` reads the index and deletes as separate operations. A
-concurrent `cache_put` between the two steps can orphan entries. Mitigated
-by AND-intersection purge semantics, but full atomicity (Lua script or
-`WATCH`/`MULTI` on the Redis backend) is still owed.
-
 ### Cross-language stringification divergence
 Python `str(True)` → `"True"` vs JS `String(true)` → `"true"`. `_normalize`
 canonicalizes `True`/`False`/`None` today, but the rules for the remaining
@@ -19,22 +15,6 @@ TypeScript HMAC keys can still diverge on an un-normalized type.
 
 ## Performance / Operability
 
-### Broad purge leaves per-param sub-indexes
-A broad `cache_purge(context)` deletes the entries but not the per-param
-sub-indexes — a slow Redis memory leak.
-
 ### No thundering-herd protection
 Concurrent cold misses on the same key all execute and write. No
 single-flight / request-coalescing.
-
-## API shape
-
-### cache_get / cache_put argument inconsistency
-`cache_get`/`cache_put` take explicit args while the executor resolves some
-inputs from module globals — two access patterns for one concern.
-
-## Coverage
-
-### RedisCache lacks test coverage
-Only `MemoryCache` is exercised by the suite. `RedisCache` (connection
-pooling, TTL, SCAN/UNLINK batching, socket timeouts) is untested.