Spec #137: per-Series poll failure state, completion hint, and outbound owner notification (#174)

Implements spec #137 (spec 4 of 4 from wayfinder map #114).

Closes #137.

Tickets: #164, #165, #166, #167, #168, #169, #170, #171, #172, #173 — all closed, landed on this branch.

## Summary
- #164/#168: sixth outcome word `not_found`; per-Site completed marker predicate.
- #165/#169: `poll_failures` row is the failure state; the pass remembers a Site-reported completion.
- #166/#171: two new admin filters (`failing`, `unverified`); outbound owner notification + stall condition.
- #167/#170: a failure names itself on the Series page; the completion hint reaches the owner and decides nothing.
- #172: the other three fault conditions (no-browser-route, sidecar-down, adapter-broken) feeding the notifier.
- #173: the landing verdict line shares the same `latest.FaultsFrom` judgement the notifier uses, so the page and the push cannot disagree.

`cd backend && go test ./...` green on the merged branch (8 packages).

Reviewed-on: #174
Co-authored-by: Sulthan Zaki <sultankiki05@gmail.com>
Co-committed-by: Sulthan Zaki <sultankiki05@gmail.com>

backend/internal/web/admin_overview.go

@@ -2,8 +2,10 @@ package web
 
 import (
 	"fmt"
+	"log"
 	"time"
 
+	"bookmarkmanager/backend/internal/latest"
 	"bookmarkmanager/backend/internal/store"
 )
 
@@ -23,10 +25,10 @@ type overviewView struct {
 	// as stale + never_checked: a never-checked Series is already counted on
 	// its own filter, and the verdict wants the inclusive number.
 	Unchecked int
-	// Hygiene is the seven problem filters in the Series list's own render
-	// order plus the finished figure riding last (informational); Library is
-	// the library split plus the roster. Every figure is a door into the list
-	// that counts it, except a zero.
+	// Hygiene is the problem filters in the Series list's own render order
+	// plus the informational tail — finished, then site completed — riding
+	// last; Library is the library split plus the roster. Every figure is a
+	// door into the list that counts it, except a zero.
 	Hygiene []fig
 	Library []fig
 	// Sites is the per-Site library shape table, one row per Site with any
@@ -60,10 +62,13 @@ type siteRow struct {
 }
 
 // overviewView assembles the landing page from the store's read model: one
-// SeriesShapes pass per filter summed in Go (the shipped surface offers nine
+// SeriesShapes pass per filter summed in Go (the shipped surface offers ten
 // grouped passes, not a stats query — #140), the pass log's latest pass per
-// Site, and the roster. A failure in any read is a 500 with a logged reason,
-// never a page of silent zeroes.
+// Site, and the roster. A failure in the SeriesShapes, pass or roster reads
+// is a 500 with a logged reason, never a page of silent zeroes. The three
+// fault-input reads (RefusingSince, SidecarOK, NoChapterShare) fail open:
+// a failing read logs and contributes no fault, so the landing page still
+// renders — the same fail-open the poller uses for owner notices.
 func (h *Handler) overviewView() (overviewView, error) {
 	now := time.Now()
 	cutoff := now.Add(-ownerWindow).UnixMilli()
@@ -92,12 +97,36 @@ func (h *Handler) overviewView() (overviewView, error) {
 
 	view := overviewView{Waiting: waiting(passes)}
 	view.Unchecked = totals[store.SeriesFilterStale] + totals[store.SeriesFilterNeverChecked]
-	view.Verdict, view.HasCounts = overviewVerdict(passes, now)
+	var refusingSince map[string]int64
+	if m, err := h.store.RefusingSince(now.UnixMilli()); err != nil {
+		log.Printf("admin overview: refusing since: %v", err)
+	} else {
+		refusingSince = m
+	}
+	var sidecarOK map[string]int64
+	if m, err := h.store.SidecarOK(latest.BrowserBackedSites()); err != nil {
+		log.Printf("admin overview: sidecar ok: %v", err)
+	} else {
+		sidecarOK = m
+	}
+	var noChapterShare map[string]float64
+	if m, err := h.store.NoChapterShare(cutoff); err != nil {
+		log.Printf("admin overview: no-chapter share: %v", err)
+	} else {
+		noChapterShare = m
+	}
+	faults := latest.FaultsFrom(latest.FaultInput{
+		Passes:         passes,
+		RefusingSince:  refusingSince,
+		SidecarOK:      sidecarOK,
+		NoChapterShare: noChapterShare,
+	}, now)
+	view.Verdict, view.HasCounts = overviewVerdict(passes, faults)
 
-	// The hygiene figures, in seriesFilterOrder's tail: the seven problem
-	// filters in permanent-then-fixable order, then the finished figure last —
-	// informational, not a problem, and last because seriesFilterOrder appends
-	// it there. The All filter's count belongs to the Library block, not to a
+	// The hygiene figures, in seriesFilterOrder's tail: the problem filters
+	// in permanent-then-fixable order, then the informational tail — finished
+	// and site completed — riding last because seriesFilterOrder appends them
+	// there. The All filter's count belongs to the Library block, not to a
 	// "hygiene" figure.
 	hygiene := make([]fig, 0, len(seriesFilterOrder)-1)
 	for _, name := range seriesFilterOrder[1:] {
@@ -165,28 +194,26 @@ func door(label string, count int, href string) fig {
 	return fig{Label: label, Href: href, Count: count}
 }
 
-// overviewVerdict decides the landing page's one line from the latest pass
-// per Site: no passes at all is "no Lane has reported yet" — never confident
-// zeroes; otherwise the count of Lanes whose last pass needs the owner, or
-// "all lanes healthy". The count comes from the same laneState judgement the
-// Lanes page colours on, so the two pages cannot disagree on what a fault is.
-func overviewVerdict(passes []store.LanePass, now time.Time) (phrase string, counts bool) {
+// overviewVerdict decides the landing page's one line: no passes at all is
+// "no Lane has reported yet" — never confident zeroes; otherwise the count of
+// faults from the shared FaultsFrom judgement, so the page and the push
+// cannot disagree. Zero faults is "all lanes healthy". A sidecar-down fault
+// carries Site == "" and is still one fault. The Lanes page's per-row
+// laneState is a different question (is this Lane's last pass healthy) from
+// the notice class, and its known false positives live there deliberately, so
+// the two now differ.
+func overviewVerdict(passes []store.LanePass, faults []latest.Fault) (phrase string, counts bool) {
 	if len(passes) == 0 {
 		return "no Lane has reported yet", false
 	}
-	attention := 0
-	for _, p := range passes {
-		if _, _, attn := laneState(p, now); attn {
-			attention++
-		}
-	}
-	if attention == 0 {
+	n := len(faults)
+	if n == 0 {
 		return "all lanes healthy", true
 	}
-	if attention == 1 {
+	if n == 1 {
 		return "1 lane needs a look", true
 	}
-	return fmt.Sprintf("%d lanes need a look", attention), true
+	return fmt.Sprintf("%d lanes need a look", n), true
 }
 
 // waiting sums Due over the latest pass per Site: how many Series the Lanes