felhom.eu/REUSE.md

REUSE.md — felhom.eu (hub + website + scripts)

Before writing new code, check here. Canonical helpers, patterns to copy, traps to avoid. Maintenance: update in the SAME commit that adds/changes/deprecates a shared helper. Entries cite file + symbol. Line numbers are landmarks only — reconfirm before editing.

1. Canonical helpers (MUST reuse — do not reinvent)

Report ingest & API auth (hub/internal/api/)

Symbol	File	Short signature	Use for	Gotchas
(*Handler).checkAuthCustomer	hub/internal/api/handler.go (~L94)	(r) (customerID string, isGlobal, ok bool)	Bearer auth for controller-facing endpoints (global key OR per-customer key)	Global key → ("", true, true): caller must then trust body customer_id. Constant-time compare on global key.
(*Handler).checkAuthHost	hub/internal/api/handler.go (~L119)	(r) (hostID, customerID string, isGlobal, ok bool)	Bearer auth for agent-facing endpoints (global OR per-host key)	Sibling of checkAuthCustomer — do NOT mix the two token namespaces. Global key requires the host row to already exist (see handleHostReport).
(*Handler).handleEvent + allowedEventTypes	hub/internal/api/handler.go (~L1115 / ~L1063)	POST /api/v1/event	The ONLY controller→hub structured-event ingest	Unknown event_type → 400 (add to the map FIRST). Accepted severities: info/warning/error/critical (critical since v0.31.0); anything else coerces to "info" — exact-match lowercase ("Critical" coerces). Tests: hub/internal/api/event_test.go.
(*Handler).handleHostReport	hub/internal/api/handler.go (~L464)	POST /api/v1/host-report	Agent heartbeat ingest: denorm + guest upsert	Body cap via LimitReader; per-host key enforces host_id match (403 on mismatch); received_at is the dead-man's-switch.
(*Handler).handleConfigRetrieve	hub/internal/api/handler.go (~L1484)	GET /api/v1/config/{id}, header X-Retrieval-Password	Canonical password-gated retrieval endpoint	Constant-time compare vs cfg.RetrievalPassword; 404-before-401 ordering. handleArtifactManifest mirrors it EXACTLY — keep them in lockstep.
writeJSON	hub/internal/api/dr.go (~L25)	(w, code int, v any)	JSON responses in api package	Only used in dr.go so far; prefer it over ad-hoc byte-writes for new endpoints.
(*mailRateLimiter).allow	hub/internal/api/mail.go (~L48)	(key string) bool	Per-key token-bucket rate limiting	Refill = perMinute/60 per sec, burst = perMinute; in-memory (lost on restart, accepted). now is injectable for tests.

Alerting / Resend / dispatcher (hub/internal/notify/, monitor/)

Symbol	File	Short signature	Use for	Gotchas
(*Dispatcher).ProcessEvent	hub/internal/notify/dispatcher.go (~L67)	(customerID, eventType, severity, message, detailsJSON, source)	THE notification pipeline (operator + customer channels, cooldowns, prefs)	Call in a goroutine (handlers do go d.ProcessEvent(...)). No Resend key → silent no-op. eventType=="test" bypasses prefs/cooldown.
severityNotifies	hub/internal/notify/dispatcher.go (~L56)	(severity string) bool	Deciding whether a severity emails	warning/error/critical notify; info intentionally doesn't; anything else is logged as unrecognized (v0.24.0 fix — do not regress).
FormatOperatorEmail / FormatCustomerEmail	hub/internal/notify/templates.go (~L24 / ~L118)	(...) (subject, body)	Operator (English) / customer (Hungarian) email bodies	Customer messages come from the customerMessages map — add the Hungarian text when adding an event type. Budapest TZ via package init().
monitor.EventNotifyFunc	hub/internal/monitor/staleness.go (~L14)	func(customerID, eventType, severity, message, detailsJSON, source)	Decoupling checkers from notify; wired to dispatcher.ProcessEvent in main	May be nil — always nil-check before calling (all checkers do).
(*Store).LogNotification	hub/internal/store/store.go (~L433)	(customerID, eventType, severity, message, status, errorMsg, channel)	Audit trail of every send attempt (sent/failed, per channel)	Log BOTH success and failure (dispatcher does).

App-mail passthrough (hub/internal/mailrelay/)

Symbol	File	Short signature	Use for	Gotchas
mailrelay.Sender / (*ResendSMTP).Send	hub/internal/mailrelay/relay.go (~L24 / ~L50)	Send(ctx, raw []byte, mailFrom, rcptTo) error	Raw-MIME passthrough to Resend SMTP	Deliberately separate from notify's HTTP path — parse-then-API drops inline CID images (spike-proven). Do NOT "unify" them. Delivery verdict lands at DATA-close.
mailrelay.FromDomain	hub/internal/mailrelay/relay.go (~L130)	(raw []byte) (string, error)	From-HEADER domain extraction for allowlisting	Header domain, not envelope — Resend checks the header.

Web auth / session / CSRF (hub/internal/web/)

Symbol	File	Short signature	Use for	Gotchas
(*Server).RequireAuth	hub/internal/web/server.go (~L359)	(next http.Handler) http.Handler	Session-cookie OR Basic-auth gate for all web routes	Empty passwordHash disables auth entirely (dev mode). Browsers → /login redirect; JSON-ish requests → 401.
(*Server).validateCSRF	hub/internal/web/server.go (~L446)	(r) bool	CSRF check — enforced centrally in web.ServeHTTP for every non-GET	No session cookie → returns true (Basic-auth path is exempt). New POST routes get CSRF for free; forms MUST embed csrfField.
(*Server).csrfField	hub/internal/web/server.go (~L483)	(r) template.HTML	Hidden _csrf input for HTML forms	Pass into template data on every form-rendering handler.
(*Server).CleanupSessions	hub/internal/web/server.go (~L110)	(ctx) — goroutine	Expired-session sweeper	Started once from main; 15-min tick.

Status tokens & template funcmap (hub/internal/web/)

Symbol	File	Short signature	Use for	Gotchas
funcMap in web.New	hub/internal/web/server.go (~L67)	template.FuncMap{...}	ALL template helpers (timeAgo, statusColor, json, hubVersion…)	Add new template funcs HERE, nowhere else. Tested by hub/internal/web/funcmap_test.go + render_test.go.
timeAgo	hub/internal/web/server.go (~L603)	(t time.Time) string	Human-relative timestamps in UI	—
statusColor	hub/internal/web/server.go (~L630)	(status string) string	Status → design-system-v2 token (nominal/warn/crit/neutral)	Class SUFFIX only, never inline color (D4). Exception-color principle: healthy = blue/neutral.
(*Server).hostStatus + hostStatusClass/hostStatusLabel	hub/internal/web/hosts.go (~L16/34/48)	(lastReport *time.Time) string	Host liveness badge	Uses the SAME threshold as HostStalenessChecker (down = 2× stale) — never invent a second definition.
parseSQLiteTime	hub/internal/store/store.go (~L1160)	(s string) time.Time	Parsing ANY timestamp read from SQLite	modernc/sqlite returns multiple formats; raw time.Parse will intermittently zero out. Always use this.
compareVersions	hub/internal/web/server.go (~L571)	(a, b string) int	X.Y.Z comparisons in web (floor checks, update-available)	Returns 0 on parse error — unparseable compares as "equal" (see §3).

Host views & lifecycle / offsite endpoints (v0.47.0, hub/internal/web + store)

Symbol	File	Short signature	Use for	Gotchas
(*Server).hostDetailData	hub/internal/web/hosts.go (~L282)	(host *store.Host, r) map[string]interface{}	The ONE view-model builder for the shared host_detail_body sub-template (standalone /hosts/{id} + customer Host tab)	Booleans/counts only for DR/escrow; carries Deletable (= status != "ok") which gates the danger-zone card. Never add a secret field.
host_detail_body sub-template	hub/internal/web/templates/host_detail_body.html	{{template "host_detail_body" .}}	Rendering a host's detail sections on ANY surface	One namespace across ParseFS (icons.html pattern). Renders per-host — id-suffix any new element ids with {{.HostID}} (the customer page renders N instances).
(*Store).ListHostsByCustomer	hub/internal/store/store.go (~L1620)	(customerID) ([]Host, error)	A customer's hosts, host_id order	A LIST by design (HA-cluster roadmap) — don't collapse to GetHostByCustomer.
(*Store).CountHostArtifacts / DeleteHost	hub/internal/store/store.go (~L1640/~L1690)	(hostID) (HostArtifacts, error) / (hostID, deleteEscrow bool) error	Host-delete impact preview + the ONE-transaction cascade	ONLINE gate lives in the handler, escrow gate in the store (ErrHostEscrowPresent, tx never starts). log_bundles die by scope_id == host_id ONLY (customer-scoped bundles survive). The wg_peers delete is INSIDE the tx — never split it out.
(*Store).ListWGEndpoints / DeleteWGEndpoint	hub/internal/store/wg.go (~L64/~L86)	() ([]WGEndpoint, error) / (endpointID) error	The /offsite endpoint-management surface	GetWGEndpoint (lowest id, LIMIT 1) stays THE allocation/sync endpoint — do not switch allocator/reconciler/desired-state to the list without the wg_peers.endpoint_id migration arc. Peers-in-subnet guards live in web/offsite.go.

Artifact manifest / Day-0 trust root

Symbol	File	Short signature	Use for	Gotchas
(*Store).GetArtifactManifest / SetArtifactManifest	hub/internal/store/store.go (~L933 / ~L944)	() ArtifactManifest / (m) error	The DB-backed (hub_settings) Day-0 artifact record	This is the checksum TRUST ROOT the host-bootstrap verifies against — distinct from Gitea, which only stores bytes.
(*Server).handleSetArtifacts + resolveArtifactSHA	hub/internal/web/configs.go (~L644 / ~L680)	POST /configuration/artifacts	Operator UI to vouch artifact versions	With a Gitea client the sha is fetched AUTHORITATIVELY (submitted sha ignored); fetch failure refuses the save. Manual sha only in the no-creds fallback.
(*gitea.Client).ListVersions / FileSHA256	hub/internal/gitea/gitea.go (~L47 / ~L72)	(ctx, pkg) ([]string, error) / (ctx, pkg, ver, file)	Read-only Gitea generic-package metadata	sha comes from package metadata — artifact bytes are never downloaded. Newest-semver-first sort.
(*Server).artifactChoices	hub/internal/web/server.go (~L155)	(ctx, pkg, file) []artifactChoice	Version+sha dropdown data	nil Gitea client / unreachable → nil → UI degrades to manual entry. One bad version drops itself, not the list.
(*Handler).handleArtifactManifest	hub/internal/api/handler.go (~L1550)	GET /api/v1/artifacts/{id}	Serving the vouched set to the bootstrap script	Auth mirrors handleConfigRetrieve exactly. Unset manifest = empty fields, not an error.
normalizeFloorInput / normalizeSHA256	hub/internal/web/configs.go (~L27 / ~L627)	(raw string) (string, bool)	Validating operator-typed versions / shas	Empty string is VALID (means "clear"). Reuse for any new version/sha form field.

PBS DR tier / tenantsync (hub/internal/tenantsync/, web/pbsdr.go, api/pbsdr.go)

Symbol	File	Short signature	Use for	Gotchas
tenantsync.Client (Provision/Reissue/Fingerprint)	hub/internal/tenantsync/client.go	(ctx, customerID) (*Result, error)	ep0 per-customer PBS tenancy over the pinned-SSH forced-command channel (the wgsync twin)	Result.TokenSecret is transient custody → SaveHostPBSSecret immediately, never log the struct. Error paths NEVER embed stdout (the secret channel) — do not "improve" diagnostics by quoting the response. ErrTokenExists is typed: provision refuses an existing token; re-issue is the explicit path.
(*Store).SaveHostPBSSecret / ConsumeHostPBSSecret	hub/internal/store/pbsdr.go	(hostID, value) / (hostID) (string, error)	HOST-scoped consume-once secret (the one_time_secrets host twin)	Same-tx mark-consumed; re-save resets consumption (re-issue supersedes). The agent consumes via POST /api/v1/hosts/{id}/pbs/consume-token (api/pbsdr.go).
(*Server).applyPBSDR + mergePBSDR/readPBSDR	hub/internal/web/pbsdr.go	(ctx, r, cfg) error	The config form's PBS DR section → HOST desired_json pbs_dr descriptor + generation bump	Descriptor lives in the host desired_json, NOT ConfigJSON (buildConfigJSON drops foreign keys on re-save). Fail-closed before SaveCustomerConfig; already-provisioned = success-no-op (red-proofed); disable keeps the ep0 tenancy.

Config generation & secrets hygiene (hub/internal/configgen/)

Symbol	File	Short signature	Use for	Gotchas
configgen.Generate	hub/internal/configgen/configgen.go (~L16)	(templateYAML, cfg) (string, error)	Producing a customer controller.yaml	Programmatic overrides (customer id/hub url/api_key) ALWAYS win over config_json; fresh session secret per generation.
configgen.RandomHex	hub/internal/configgen/configgen.go (~L110)	(n int) (string, error)	crypto/rand hex tokens (API keys, session secrets)	—
configgen.RandomPassphrase	hub/internal/configgen/passphrase.go (~L35)	(wordCount int) (string, error)	Human-dictatable Hungarian passphrases (retrieval passwords)	~29K-word embedded list; 5 words ≈ 74 bits.
(*Store).EffectiveMinControllerVersion	hub/internal/store/store.go (~L960)	(customerID) string	Resolving the floor that actually applies (per-customer → global)	"" = no floor (Phase 2 inert).

Assets, store misc, scheduling

Symbol	File	Short signature	Use for	Gotchas
assets.Manager (New, ServeFile, ReSeed)	hub/internal/assets/assets.go (~L44/190/122)	seed-dir → PVC sync + manifest	Serving app logos/screenshots to controllers	ServeFile sanitizes to filepath.Base (no traversal). isAssetFile enforces the naming convention.
copyFile	hub/internal/assets/assets.go (~L259)	(src, dst) error	THE atomic file write (tmp + rename) in the hub	Copy this shape for any new on-disk write.
fileSHA256	hub/internal/assets/assets.go (~L244)	(path) (string, error)	Streaming sha256 of a file	—
(*Store).SaveEvent	hub/internal/store/store.go (~L1003)	(...) (int64, error)	Persisting ANY event (controller or hub source)	Pair with dispatcher/onEvent — saving alone never notifies.
(*Store).RequestLogTail / GetPendingLogTailRequests / SaveAppLogTail	hub/internal/store/logtail.go	pending-intent + consume-once fulfillment	THE ACK-flag pull pattern for hub→box requests (copy for any new one)	SaveAppLogTail clears the request in the SAME tx (consume-once) + prunes to last 2 per (customer,app); the hub NEVER connects into a box
(*Store).RequestLogBundle / PendingLogBundleRequest / SaveLogBundle / PurgeExpiredLogBundles	hub/internal/store/logbundle.go	component (controller/agent) log pulls — the v0.46.0 sibling of logtail.go	box-component debug-ring pulls; gzip custody, newest-3, 72 h TTL on the 60 s sweep	scope = customer_id (controller/report ACK) vs host_id (agent/heartbeat envelope); SaveLogBundle runs the SECRET GATE fail-closed (blocked flag row, no payload) and clears the request in the same tx; [REDACTED]/checksums pass by design
upsertAppIssue dismissal/context semantics	hub/internal/store/telemetry.go	ON CONFLICT CASE guards	Issue dismissal + first-capture-wins context	Un-dismiss ONLY on excluded.last_seen > dismissed_at; context adopted only while stored one is empty — do not "simplify" either CASE (red-proofed)
store.GuestID	hub/internal/store/store.go (~L1268)	(hostID string, vmid int) string	Canonical guest primary key	Never hand-concatenate host+vmid.
scheduleDaily	hub/cmd/hub/main.go (~L449)	(ctx, name, "HH:MM", fn, logger)	Daily jobs in Europe/Budapest (prune etc.)	Blocking — run as goroutine. parseHM returns 0,0 (midnight) on bad input.

2. Canonical patterns (copy structure from THE named file)

Pattern	Canonical file	Key traits
Monitor checker	hub/internal/monitor/staleness.go	Seed state on construction WITHOUT emitting events; in-memory states map under mutex; periodic Check(); emitTransition = SaveEvent then nil-checked onEvent; cleanup of vanished IDs. HostStaleness/HostDisk/HostLeaf/HostCapability/StorageFill all follow it.
API endpoint	hub/internal/api/handler.go ServeHTTP (~L139) + any handler	Path switch in ServeHTTP; first line of every handler = checkAuth{Customer,Host}; io.LimitReader body cap; typed anonymous payload struct; explicit 4xx strings.
Web POST action	hub/internal/web/configs.go handleSetGlobalFloor (~L602)	CSRF enforced centrally in web ServeHTTP; validate via normalize* helper; POST-redirect-GET with ?flash= token; log INFO on success.
Optional dependency injection	hub/internal/web/server.go Set* setters (~L131–148) / api handler SetDispatcher etc.	Constructor takes hard deps; optional subsystems wired via SetX after construction; nil = graceful degradation (never panic).
Seam-injected sender for tests	hub/internal/notify/dispatcher.go sendEmailFn (~L33)	Function-field defaulting to the real impl in the constructor; tests overwrite it. Same idea: mailRateLimiter.now, mailrelay.Sender fake.
Website page	website/index.html	UTF-8 with BOM; shared <nav>/<footer> byte-identical across pages (only class="active" differs); two-tone H1 = <h1>…<span>accent</span></h1>; all styling in website/assets/site.css tokens (:root) — zero embedded <style>; ?v=N cache-bust on site.css/icons.svg; umami snippet; no CDN fonts; no emoji (sprite icons.svg instead).
Gate script	scripts/site_gates.py	Byte-level mechanical gates (BOM, emoji codepoint ranges, nav/footer diff, analytics, banned tokens, cache-bust); run python scripts/site_gates.py after ANY website change; non-zero exit on failure.
Fetch-validate-install (shell)	scripts/felhom-host-install.sh step_agent_install (~L1108)	fetch_raw to mktemp → syntax-check (bash -n) → install -m0755 -o root -g root → only then activate; guarded-mkfs wrapper installed BEFORE the sudoers that references it (ordering is the safety property). All mutations through run() (dry-run aware).
Install-profile gate (shell)	scripts/felhom-host-install.sh --mode appliance|byo (GL-2, v1.10.0)	Mandatory-flag profile (no default), refusals at argv time BEFORE any prompt/step, risky step gated at its CALL SITE (one auditable place — never a branch inside the step), mode persisted to state.json + resume-mismatch refusal, FELHOM_INSTALL_STATE_DIR override for harness isolation. Harness: scripts/hostinstall-mode-harness.sh (static refusal matrix + grep-invariants + PVE dry-transcript tier; red-proofs run against a mutated scratch copy).
Disclosure↔uninstall parity (shell)	scripts/felhom-host-install.sh _uninstall_statement + harness GL4-D (v1.11.0)	Every host artifact the byo disclosure names must be removed OR explicitly listed KEPT by run_uninstall; the harness greps the parity (token list). New install-time artifact ⇒ add its removal + disclosure line + parity token in the SAME commit. Drive data rule: plain umount only, never -l/-f, never any format op under /mnt/felhom-drives.
Website deploy (manifest)	manifests/webpage.yaml	git-sync sidecar (sparse-checkout /website/ + /scripts/, --link=current) + init container waits for first sync; nginx serves current/website; push to main = deployed, no image build.
Secret handling (manifest)	manifests/hub.yaml (env, ~L142)	Secrets via secretKeyRef to OUT-OF-BAND secrets created per documentation/runbooks/secrets.md — never inline stringData (see §3). ERRATA (2026-07-03): only resend-api is truly out-of-band today; gitea-creds is COMMITTED in manifests/felhom.secret.yaml AND live-consumed by hub.yaml — rotation + de-git is a pending operator task (spike SPIKE-a1 appendix).
Hub deploy (GitOps)	manifests/hub.yaml image: (~L129)	Pinned explicit tag, bumped in git, deliberate ArgoCD sync (auto-sync OFF). Code push alone deploys nothing.

3. Dangerous lookalikes — do NOT reuse

Trap	Why it bites	Use instead
(*Handler).handleNotify + formatNotificationEmail + sendResendEmail (hub/internal/api/handler.go ~L1289/1624/1589)	Legacy pre-dispatcher notification trio: no cooldowns, no operator channel, no allowedEventTypes gate, duplicate Hungarian formatter. Controller path is FROZEN until slice-10 cutover.	POST /api/v1/event → Dispatcher.ProcessEvent + notify.Format*Email
Severity "critical" POSTed to a PRE-v0.31.0 hub	Fixed in hub v0.31.0 (handleEvent now accepts critical). Older hubs coerce critical → "info", which never notifies — silent alert loss. Case-variants ("Critical") still coerce on every version.	Against an old hub send warning/error; otherwise lowercase critical is safe
compareVersions for anything security-ish (hub/internal/web/server.go ~L571)	Returns 0 (equal) on unparseable input — a garbage version passes a floor check. gitea.compareSemver behaves differently (lexical fallback).	Validate input with normalizeFloorInput first; then compareVersions is safe
Inline stringData secrets à la manifests/felhom.secret.yaml	Commits real credentials to git (healthchecks superuser pw, umami APP_SECRET/POSTGRES_PASSWORD, gitea-creds admin password still live there).	Out-of-band kubectl create secret + secretKeyRef (hub.yaml resend-api pattern; runbook documentation/runbooks/secrets.md)
kubectl apply / kubectl set image on manifests/	ArgoCD app felhom reverts drift on next sync; live state lies about git.	Edit manifest in git → push → ArgoCD sync (CLAUDE.md steps 3–5)
:latest image tag in manifests	Re-push doesn't change the manifest → no redeploy; Synced/Rollback misreport.	Pinned version tag, bumped per deploy
grep/regex hunting emoji in website HTML	Windows grep false-negatives multibyte emoji (proven in D0).	python scripts/site_gates.py (codepoint-range check)
Adding a website page without touching site_gates.py	PAGES list (scripts/site_gates.py ~L22) is explicit — an unlisted page is silently ungated (BOM/nav/emoji drift undetected).	Add the filename to PAGES in the same commit

4. Seams & interfaces (testing + cross-repo)

Interface	Defined in	Implemented by	Fakes/tests at
mailrelay.Sender	hub/internal/mailrelay/relay.go (~L24)	ResendSMTP (prod)	fake sender in hub/internal/api/mail_test.go; hub/internal/mailrelay/relay_test.go
Dispatcher.sendEmailFn (func seam)	hub/internal/notify/dispatcher.go (~L33)	(*Dispatcher).sendEmail (Resend HTTP)	hub/internal/notify/dispatcher_test.go
monitor.EventNotifyFunc	hub/internal/monitor/staleness.go (~L14)	closure over Dispatcher.ProcessEvent (main.go)	hub/internal/monitor tests (captured-events func)
api.ConfigTemplateProvider	hub/internal/api/handler.go (~L24)	web.TemplateFetcher (Gitea-pulled controller.yaml template)	stub providers in api tests
api.LatestVersionProvider	hub/internal/api/handler.go (~L31)	web.VersionChecker (registry poll)	hub/internal/api/config_version_ack_test.go
mailRateLimiter.now (func seam)	hub/internal/api/mail.go (~L27)	time.Now	hub/internal/api/mail_test.go clock injection
web.tenancyProvisioner	hub/internal/web/pbsdr.go	*tenantsync.Client (pinned SSH to ep0's felhom-tenantsync)	fakeTenancy in hub/internal/web/pbsdr_test.go; in-process SSH server in hub/internal/tenantsync/client_test.go
Cross-repo: ep0 tenancy surface	scripts/felhom-tenantsync.sh (JSON stdin/stdout forced command)	installed on ep0 per runbook offsite-endpoint.md §10	provision/reissue/fingerprint ops; token secret rides stdout ONLY; the peersync script/key are untouched
Cross-repo: controller → hub	POST /api/v1/report (frozen) + POST /api/v1/event	felhom-controller repo	new event types MUST enter allowedEventTypes (hub/internal/api/handler.go ~L1063) or the controller gets 400
Cross-repo: agent → hub	POST /api/v1/host-report, /host-enroll, jobs/desired-state/escrow routes (handler.go ~L145–189)	felhom-agent repo	hub/internal/api/host_test.go, desired_test.go, escrow_test.go, dr_test.go
Cross-repo: Day-0 bootstrap → hub	GET /api/v1/config/{id} + /artifacts/{id} (X-Retrieval-Password)	scripts/felhom-host-install.sh (fetches + sha256-verifies against the hub-vouched manifest)	hub/internal/api/artifact_test.go
Cross-repo: controller ← hub assets	GET /api/v1/assets/manifest + /assets/file/{name}	felhom-controller pulls app logos/screenshots	assets manifest sha-based change detection

5. Extension points (where new features plug in)

• New event type: add to allowedEventTypes (hub/internal/api/handler.go ~L1063) and customerMessages (hub/internal/notify/templates.go) and the customer-prefs default list if customer-notifiable. Missing the first = controller POST 400s (the known gotcha).
• New monitor checker: copy hub/internal/monitor/staleness.go (§2 pattern); wire in hub/cmd/hub/main.go with an EventNotifyFunc; severity must be warning/error/critical to notify.
• New API route: switch in api.ServeHTTP (handler.go ~L139); auth helper first line.
• New web page/action: switch in web.ServeHTTP (server.go ~L182) — non-GET gets CSRF automatically; template into hub/internal/web/templates/ (embedded FS, parsed in web.New); new helpers into the funcMap (server.go ~L67).
• New template func: funcMap in web.New only; add a case to hub/internal/web/funcmap_test.go.
• New daily job: scheduleDaily in hub/cmd/hub/main.go + add pruning to pruneAll if data grows.
• New site gate: append to scripts/site_gates.py; new website pages go into its PAGES list.
• New artifact kind (Day-0): consts pkg*/file* (hub/internal/web/server.go ~L27), ArtifactManifest fields + settings keys (hub/internal/store/store.go ~L905), handleSetArtifacts, artifactManifestResponse (handler.go), and the install script's verify step.
• New host-install step: step_* function in scripts/felhom-host-install.sh using run()/fetch_raw/die helpers; keep dry-run coverage.

6. Known duplication (observed — NOT fixed)

• Resend HTTP sender ×2: (*Handler).sendResendEmail (hub/internal/api/handler.go ~L1589) ≈ (*Dispatcher).sendEmail (hub/internal/notify/dispatcher.go ~L185) — byte-near-identical POST to api.resend.com. Kept because the handler copy serves the frozen legacy /notify path.
• Hungarian customer-email formatter ×2: formatNotificationEmail (hub/internal/api/handler.go ~L1624) vs notify.FormatCustomerEmail (hub/internal/notify/templates.go ~L118). Legacy vs dispatcher; the legacy one lacks the per-event-type message map.
• Semver compare ×2 with DIFFERENT fallback semantics: web.compareVersions (hub/internal/web/server.go ~L571, parse error → 0) vs gitea.compareSemver (hub/internal/gitea/gitea.go ~L115, parse error → lexical). Documented as deliberate (import-cycle avoidance) in gitea.go, but the behavior drift is not.
• Checker-family structural repetition: staleness.go vs host_staleness.go, and host_disk.go vs storage_fill.go (band/bandRank/bandLabel vs bandForPercent) — same skeleton re-implemented per domain; treated as the accepted §2 pattern rather than a defect.
• Duration formatting ×2: monitor.formatDuration (hub/internal/monitor/staleness.go ~L187) vs web.timeAgo (hub/internal/web/server.go ~L603) — different audiences (email vs UI) but overlapping logic.