The router.SecureProvider interface previously required a public
IsSecure() bool method. Any test mock — or future production type —
could satisfy it by returning true, defeating the W1 "only wrapped
providers may flow past the boundary" contract through convention
rather than at the type level.
Replaces IsSecure() bool with an unexported security.Marker interface
that has a single secured() method. Go's method-set semantics key
unexported methods by their defining package, so only types declared in
internal/security can satisfy Marker. *SafeProvider gets the lone
secured() implementation; router.SecureProvider embeds Marker.
The seal forces every test mock that previously implemented IsSecure()
to either (a) be wrapped with security.WrapProvider(mp, nil) at the use
site, or (b) drop the method entirely if the mock never flows through
SecureProvider. 93 use sites across 11 test files were updated via a
per-package secureMock helper. WrapProvider with a nil firewall ref is
a no-op pass-through, so test behavior is unchanged.
Empirically: a type from outside internal/security can declare
`secured()` but the compiler will reject assigning it to
router.SecureProvider because the unexported method belongs to the
other package's namespace. Convention → compile-time guarantee.
Adds three lightweight per-turn detectors that fire corrective user
messages back into the conversation when the model goes off the rails:
- RepetitionDetector: sliding-window scan over streamed text deltas;
trips when a 50/80/120-char pattern repeats >= 3 times in the trailing
200 chars. Breaks the active stream and injects a correction.
- PatchFailureTracker: per-path counter for fs.edit/fs.write failures;
trips on the 4th consecutive failure and steers the model to fs.write
rather than another fs.edit on the same path. Success decrements with
a floor of 0; paths are isolated.
- DetectGreeting: narrow allowlist for "how can I help" style replies;
only consulted after a round that used tools, so first-turn greetings
don't false-positive.
Detector state is per-turn (declared locally in runLoop), single-
goroutine use. Corrective messages are appended as user-role text to
both engine history and the context window. Telemetry: each trigger
logs at INFO with round + path where applicable.
Covered by 12 unit tests for the primitives and 5 loop-level integration
tests that drive the full agentic loop via the existing eventStream
mock.
vikingowl