Honesty: model-name _Nk suffix presented as verified context window; telemetry default-on invisible

[Hmbown]

Two honesty findings from the self-improving-harness audit (same class as
#5239/#5440 — guesses rendered as verified facts).

1 — _Nk name-suffix hint has no provenance and is optimistic

crates/tui/src/models.rs:547-572 (explicit_context_window_hint): any
digit-K run in a model name yields a context window, vendor-agnostic,
consulted at models.rs:170-172 ahead of the conservative heuristics.
A self-hosted qwen3-32b-256k shows "256K" in inventory/picker
(model_inventory.rs:110-166) and drives compaction math
(route_budget.rs:31-48) with no marker that it was parsed from a name
convention the serving engine may not honor.

Unlike the 128K fallback (conservative), this rung is optimistic: if the
engine serves less, compaction fires too late and the request fails at the
provider instead. When #5239's ContextWindowSource provenance lands, the
_Nk rung must land as unverified/Fallback — never Catalog — and the
surfaces must say so. Cross-link: belongs in the #5239 test matrix.

2 — Telemetry resolves ON by default; no surface reports the defaulted state

crates/config/src/lib.rs:3421-3442: telemetry = cli.or(env).or(config).unwrap_or(true).
Display: get_value("telemetry") returns None when unset (lib.rs:2830) —
reads as "unset" in config UI while batches ship. The runtime-posture doctor
section lists sandbox/approval/network with sources (crates/tui/src/lib.rs:6325-6352)
but has no telemetry row. A user who never opted in sees nothing saying
"telemetry: on (default)".

Fix: one doctor row + config display showing the resolved value with its
source (default | env | config). Not a behavior change — a truth change.

Acceptance

• _Nk-derived windows carry unverified provenance end-to-end (picker, inventory, compaction).
• The model supports 1M context, but why does the tool only trigger context compression at 128K #5239 test matrix gains a _Nk case.
• Doctor + config display show resolved telemetry with source.