chore: merge release v1.4.5 to main (#1142)

* chore: bump version to 1.4.5 for hotfix

* fix(#1133): honor model_policy on the claude runtime via alias mapping

model_policy (including the anthropic-fable Claude Fable 5 preset) was
silently ignored on the default `claude` runtime: resolveModelInternal
gated the policy branch on `runtime !== 'claude'`, so agents kept
resolving from model_profile and no warning was emitted.

Wire model_policy into the claude path: map the policy-resolved model ID
back to a Claude Code agent alias (claude-fable-5 -> fable, claude-opus-4-8
-> opus, etc.). A value that is already a bare alias is returned as-is; an
ID with no Claude alias warns once to stderr and falls back to the
configured tier alias rather than emitting an unspawnable ID. Non-claude
runtimes return full IDs verbatim (unchanged) and resolveModelForTier
precedence is unchanged.

Authored against the v1.4.4 base (src/core.cts) for the 1.4.5 hotfix
line — NOT next, where this logic lives in src/model-resolver.cts; the
forward-port to next is a separate follow-up.

Closes #1133

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

* chore: promote CHANGELOG for v1.4.5

---------

Co-authored-by: github-actions[bot] <41898282+github-actions[bot]@users.noreply.github.com>
Co-authored-by: Claude Opus 4.8 <noreply@anthropic.com>

CHANGELOG.md

@@ -6,6 +6,12 @@ Format follows [Keep a Changelog](https://keepachangelog.com/en/1.1.0/).
 
 ## [Unreleased]
 
+## [1.4.5] - 2026-06-12
+
+### Fixed
+
+- **`model_policy` is now honored on the default `claude` runtime** — including the `anthropic-fable` Claude Fable 5 preset. Policy-resolved model IDs map to Claude Code agent aliases (e.g. `claude-fable-5` → `fable`), and IDs without a Claude alias warn and fall back to the configured tier. Previously the entire `model_policy` block was silently ignored on `claude`. (#1133) (#1133)
+
 ## [1.4.4] - 2026-06-11
 
 ### Changed