[Hackathon] Debug diagnostics for suppressed skill-nudge errors

[yuhaouno]

Summary

This is a narrow, independently reviewable subtask of #186 covering the two remaining src/lib/skill-nudge.ts silent catch paths.

The global --debug flag is not currently passed into the skill-nudge pre-action, so a failed profile lookup silently skips the nudge and an unreadable managed skill target is silently treated as absent. Those failures leave operators without a diagnostic even when they requested debug output.

Expected behavior

• With --debug, write an actionable diagnostic to stderr for each swallowed failure.
• Without --debug, preserve the existing warning text, output mode behavior, and exit status exactly.
• Never pollute JSON stdout or let a failing diagnostic sink break the command.

Scope

• Thread the parsed global debug flag into the pre-action nudge context.
• Add debug-only diagnostics for the profile-lookup and managed-target read failures.
• Add regression coverage for debug output and byte-identical non-debug behavior.

Relationship

Part of #186; deliberately split so this PR can close a concrete, scoped issue without closing the broader tracker.

[yuhaouno]

/assign

[testsprite-hob]

Assigned to @yuhaouno. Thanks for taking this on. (1 more slot available.)

Your open assigned issues (2/3):

• [Hackathon] Add structured debug logging to silent catch blocks #186 — [Hackathon] Add structured debug logging to silent catch blocks

[zeshi-du]

@yuhaouno closed #284 without a comment, so this is unclaimed again. Genuinely no hard feelings if you'd rather not continue — but I should note the PR had sat with two failing gate checks and zero reviews for 18 days before you abandoned it, which is a fair reason to walk away and is on us.

The gap is still real and still small. Both catch {} blocks in src/lib/skill-nudge.ts swallow their errors even under --debug, because the debug flag isn't threaded into the pre-action nudge context — so when the nudge silently doesn't fire, there's no way to find out why.

#223 is the pattern to copy: structured debug emission through the existing flag, with a test. Open for anyone.

[stuart902]

/assign

[testsprite-hob]

Assigned to @stuart902. Thanks for taking this on. (2 more slots available.)

Your open assigned issues (1/3):
(none)