detectCapabilities previously disabled hyperlinks under tmux unconditionally. tmux re-emits OSC 8 to the outer terminal only when the attached client advertises the 'hyperlinks' feature in client_termfeatures, and strips them otherwise.
Probe the running server with 'tmux display-message -p #{client_termfeatures}' and enable hyperlinks only when the feature is listed. The probe fails closed: any error (no tmux/server, timeout, old tmux) yields false. images stays null; only the hyperlink decision changed. The probe is injected into detectCapabilities so it stays testable without spawning a process.
Wrap the path shown in read/write/edit/ls tool titles in an OSC 8 file:// hyperlink when the terminal advertises hyperlink support.
The link target is always the absolute path, while the visible text stays relative/home-shortened and line annotations (e.g. :120-140) are kept out of the target.
Honour StreamOptions.headers in the Bedrock provider by attaching a
Smithy build-step middleware that merges caller headers into the
request before SigV4 signing. Reserved headers (x-amz-*, authorization,
host) are silently skipped to preserve signing and the bearer-token
auth path. No-op when no headers are supplied. Updates the
StreamOptions.headers JSDoc to drop the Bedrock caveat.