fix(cache): make the ttl parameter actually control expiry (#450)

CacheManager.set(key, data, ttl=...) stored the number and no read path
ever consulted it. Expiry came from a max_age inferred from substrings
in the key -- "live", "odds", "stock" -- so all 52 callers passing a ttl
were writing a value that did nothing. The docstring said so outright:
"stored for compatibility but expiration is still controlled via max_age
when reading". It is easier to read that as a note than as a defect,
which is presumably how it survived.

Both cache layers already hold the record when they decide, so each now
prefers an explicit ttl and falls back to max_age when there is none.
The caller that wrote the record knows what its data is; a substring
guess is a reasonable default for records that never said, and a poor
override for records that did.

Measured against a device's real cache of 8,875 entries carrying a ttl,
the inferred and intended values disagreed nearly everywhere:

    stocks    max_age  600  vs ttl    1800   4903 entries
    news      max_age 3600  vs ttl     600   1770 entries
    odds      max_age 1800  vs ttl    3600   1301 entries
    images    max_age  300  vs ttl 2592000     20 entries

In every case the ttl matches what the plugin plainly intended: stock
quotes cached for half an hour rather than ten minutes, headlines
refreshed every ten minutes rather than hourly, bird photographs that
never change kept for a month rather than five minutes.

Two things make this safe to land now. No sports_live entry carries a
ttl at all -- the live-score path does not use set(ttl=) -- so live
freshness is untouched, which matters with a season two weeks out. And
replaying the change against that real cache, 997 currently-expired
entries become live while not one live entry becomes expired, so there
is no invalidation spike on deploy.


Claude-Session: https://claude.ai/code/session_01Udr6MfaFLUPhX5Fgo67Jf5

Co-authored-by: Claude Opus 5 (1M context) <noreply@anthropic.com>

src/cache/disk_cache.py

@@ -112,6 +112,22 @@ class DiskCache:
                     record_ts = None
             
             now = time.time()
+
+            # An explicit per-entry ttl wins over the caller's max_age. The
+            # caller that wrote the record knows what its data is; max_age is
+            # inferred from substrings in the key ("live", "odds", "stock") and
+            # is only a fallback for records that never said. Until now the ttl
+            # was stored and ignored, so `set(key, data, ttl=...)` did nothing
+            # at all -- 48 plugin call sites and 4 in the core were writing a
+            # number no read path consulted.
+            effective_max_age = max_age
+            if isinstance(record, dict):
+                stored_ttl = record.get('ttl')
+                if isinstance(stored_ttl, (int, float)) and not isinstance(stored_ttl, bool) \
+                        and stored_ttl >= 0:
+                    effective_max_age = stored_ttl
+            max_age = effective_max_age
+
             # max_age=None means "never expires" (mirrors MemoryCache and the
             # cache_manager docstring). Guard it explicitly — otherwise the
             # comparison below raises TypeError and the record is treated as a