matrix-synapse: NOTES.txt and the exponential-quantity fix (7.1.0+upv1.159.0)

Two additive changes, neither of which alters a rendered object.

NOTES.txt (Teil von #43): prints what an operator would otherwise have to
read out of the templates - the rendered access URL or the port-forward
command, the field the 1Password item must carry (homeserver.yaml) plus the
four settings inside that file which this chart's mounts dictate, and the
chart's own traps: the split between matrix.delegation.serverUrl and
ingress.domain, the immutable server name, that a changed 1Password item does
not restart the StatefulSet while the delegation nginx does roll on a config
change, and that the PVC with signing key and media is deleted with the
release. Conditional on the values actually set: Ingress on/off, delegation
on/off, either workload scaled to zero, more than one Synapse replica, and a
matrix.env that is set. No real domain anywhere; the URLs render from the
values.

_helpers.tpl (Teil von #157): the canonical formatNumber helper, taken over
unchanged from template-chart. multiplyQuantity turned its input into a string
with printf "%v"; values that came back from fromYaml as float64 switched to
exponential notation from about 1e6 upwards, so a bare byte count like 1048576
became "1.048576e+06" and the render aborted. Both resource paths of this
chart were affected - matrix.resources in the StatefulSet and
matrix.delegation.resources in the delegation Deployment.

Minor bump, appVersion unchanged.

matrix-synapse/templates/_helpers.tpl

@@ -67,7 +67,7 @@ Handles plain numbers ("2", "0.5", 1073741824), decimal ("1.5Gi"), binary
 results are printed without a decimal point.
 */}}
 {{- define "matrix-synapse.multiplyQuantity" -}}
-{{- $quantity := printf "%v" .quantity -}}
+{{- $quantity := include "matrix-synapse.formatNumber" .quantity -}}
 {{- $number := regexFind "^[0-9]+(\\.[0-9]+)?" $quantity -}}
 {{- if not $number -}}
 {{- fail (printf "cannot parse resource quantity %q" $quantity) -}}
@@ -80,7 +80,24 @@ results are printed without a decimal point.
 {{- if eq $product (floor $product) -}}
 {{- printf "%d%s" (int64 $product) $suffix -}}
 {{- else -}}
-{{- printf "%v%s" $product $suffix -}}
+{{- printf "%s%s" (include "matrix-synapse.formatNumber" $product) $suffix -}}
+{{- end -}}
+{{- end -}}
+
+{{/*
+Render a number as a plain decimal string, never in exponential notation.
+
+Why this exists (issue #157): the null-safe fallback helpers pass values
+through fromYaml, which parses every number as float64. Go's "%v" switches
+float64 to exponential notation from about 1e6 upwards, so a bare byte count
+like 1048576 became "1.048576e+06" - not a valid Kubernetes quantity, and the
+render aborted. Strings ("512Mi") are passed through untouched.
+*/}}
+{{- define "matrix-synapse.formatNumber" -}}
+{{- if kindIs "float64" . -}}
+{{- regexReplaceAll "\\.?0+$" (printf "%.10f" .) "" -}}
+{{- else -}}
+{{- printf "%v" . -}}
 {{- end -}}
 {{- end -}}