* fix(skills): load SKILL.md saved as UTF-8 with a BOM
The front-matter anchor began at ^---, so the U+FEFF that Windows Notepad and
PowerShell's `Set-Content -Encoding UTF8` prepend made the match fail. parse_skill_file
then returned None and the catalog builder dropped the skill without logging, leaving an
author with a valid SKILL.md that simply never appears. split_skill_markdown reported
"No YAML frontmatter found" for the same file at install time.
Let the anchor consume one leading byte-order mark, and reuse the shared compiled pattern
in parser.py instead of the duplicated inline copy so the two cannot drift apart again.
* fix(skills): capture the description of a BOM-prefixed SKILL.md
The reader in skill_context anchored on ^---, so the byte-order mark that this change already
tolerates in the loader and validator made the match fail and build_skill_entry_metadata_from_read
capture an empty description. render_skill_context then listed the skill without the one line the
active-skill reminder shows for it.
Consume one leading byte-order mark there and pin the capture with a regression test.
* feat: emit structured runtime metadata
* fix: avoid subagent import cycle in replay gateway
* fix: preserve legacy subtask result parsing
* refactor: tighten runtime metadata contracts
* fix(middleware): keep recovery hint on task exception wrapper content
The structured-metadata stamp overwrote the wrapper text with the bare
task-failure message, dropping the model-facing 'Continue with available
context, or choose an alternative tool.' guidance that every other tool
exception keeps. Append the shared hint after the formatted message.
* fix(subagents): require lowercase hex for result_sha256 reader
Length-only validation accepted any 64-char string; a faulty serializer
or relaying wrapper could store a non-digest value in the delegation
ledger. Enforce the producer's hexdigest shape with a fullmatch.
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Co-authored-by: Willem Jiang <willem.jiang@gmail.com>
