Hera-managed tasks visible in task list by default + worker indicator

[drn]

Summary

• Flip the H hide-hera toggle to default OFF: hera-spawned workers and live coordinators are now visible inline in the Tasks tab instead of hidden. H still toggles — it now hides them rather than revealing.
• Add a per-row worker indicator glyph (theme.IconWorker, dim account glyph) in the hera-role indicator cell, alongside the existing coordinator glyph. Coordinator outranks worker when a task qualifies as both.
• Plain/freelancer tasks render no hera indicator (the name column reclaims the cell), unchanged.

Why

Hera-managed tasks living only in the Hera tab made a chunk of live work invisible on the primary navigation surface — you had to remember to press H to see workers a coordinator spawned. Making them visible-by-default only reads well once workers are also visually marked, hence the worker glyph (coordinators already had one).

Test plan

• make pre-pr: build / vet / fmt-check / lint-pr pass; test-cover-gate green at 89.5% ≥ 88 floor (taskview 94.8%, theme 100%). vuln reports Go stdlib-only CVEs (toolchain version), which run continue-on-error: true in CI and don't block — fails identically on a clean origin/master.
• New render tests: worker glyph drawn; coordinator-outranks-worker; plain task draws no hera cell.
• Flipped default tests: VisibleTaskIDs() includes workers + coordinators by default; H hides them; freelancer/plain always visible; composes with the substring filter. Smoke test (TestSmoke_HideHeraWorkersInTasksTab) updated to the new default.

Notes

• Spec-driven: archives the hera-tasks-visible-by-default openspec change into the task-list-view base spec in the same PR.
• Help modal H text ("show/hide hera-managed (workers+coords)") stays accurate — no key added/removed.
• A separate hera-handoff-association openspec proposal exists locally but is intentionally excluded from this PR: it's unimplemented and its design is being revised (lightweight task-edge model vs. coordinator auto-promotion).

🤖 Generated with Claude Code

Co-Authored-By: Claude noreply@anthropic.com

[github-actions]

Merging this branch will increase overall coverage

Impacted Packages	Coverage Δ	🤖
github.com/drn/argus/internal/tui	83.99% (ø)
github.com/drn/argus/internal/tui/taskview	94.82% (+0.02%)	👍
github.com/drn/argus/internal/tui/theme	100.00% (ø)

---

Coverage by file

Changed files (no unit tests)

Changed File	Coverage Δ	Total	Covered	Missed	🤖
github.com/drn/argus/internal/tui/taskview/tasklist.go	94.56% (+0.03%)	570 (+3)	539 (+3)	31	👍
github.com/drn/argus/internal/tui/theme/theme.go	100.00% (ø)	5	5	0

Please note that the "Total", "Covered", and "Missed" counts above refer to code statements instead of lines of code. The value in brackets refers to the test coverage of that file in the old version of the code.

Changed unit test files

• github.com/drn/argus/internal/tui/hera_smoke_test.go
• github.com/drn/argus/internal/tui/taskview/hera_workers_test.go
• github.com/drn/argus/internal/tui/taskview/tasklist_test.go

[anutron]

SGTM!