Update() routed form and confirm-delete states before handling
time.Time ticks, so those handlers swallowed the tick command and
permanently broke the refresh loop. After opening any form or
delete dialog, the TUI stopped auto-refreshing until restarted.
Move time.Time and WindowSizeMsg handling before state dispatch
so ticks always fire regardless of view state.
Also fix fmtRetries off-by-one: FailureCount=1 displayed as 0/N
instead of 1/N due to an erroneous subtract-one.
Categorize raw error strings into DNS/TCP/TLS/HTTP/ICMP/TMO/PRIV
so users get instant triage from the monitor list without opening
the detail panel.
- Status column shows DOWN:DNS, DOWN:TLS, DOWN:HTTP, etc.
- Inline NAME column errors prefixed with category tag [DNS], [TLS]
- Detail panel shows connection chain checklist for HTTP monitors
(✓ DNS → ✓ TCP → ✗ TLS → · HTTP) pinpointing failure layer
- All display-side only — no database or model changes
tui.go (1032→164) and tab_sites.go (993→482) violated "small functions"
and "testable in isolation" standards. Extracted 6 new files by concern:
- format.go: pure formatting functions (fmtLatency, fmtUptime, etc.)
- sparkline.go: sparkline rendering (latency, heartbeat, group)
- update.go: Update method decomposed into 15 named handlers
- view_dashboard.go: View, dashboard composition, tab bar, footer
- view_detail.go: site detail panel
- data.go: data refresh with extracted sortSitesForDisplay/filterSites
Added 17 unit tests for the newly-testable pure functions covering
format, sparkline, sort ordering, and filter logic. No behavioral
changes — strict move-and-extract refactor.