feat: Phase 1 — extract the client (web SPA + desktop) to dtoro/oikos-web

Problem: the hexagonal refactor churns the backend tree for nine more
phases; the UI delivery stack (web/ SPA, cmd/desktop Wails wrapper,
compose/web image) must move to its own repo first so doc/layout
rewrites land once on a backend-only tree.

Change:
- New repo git.hubris.network/dtoro/oikos-web (v0.33.0): web/, desktop/
  (updateURL repointed to oikos-web releases), compose/, own CI (web +
  desktop jobs), own deploy script (CI-green gate, TOCTOU guard,
  version-tagged images, prune-to-3), own webhook receiver on :9798 +
  launchd unit, own compose project publishing the same 8091:80.
- Cutover executed on mac-mini in order: oikos stack's web service
  stopped+removed, oikos-web project brought up on 8091; outer Caddy
  untouched (targets the published port) — serving + Authentik flow +
  /wails 404 quirk verified post-cutover.
- Stripped from oikos: web/, cmd/desktop/, compose/web/, desktop CI
  workflow, ci.yml web job, Makefile ui/desktop/desktop-package/install
  targets, the compose web service, oikos-web from deploy.sh's fallback
  prune list; wails + go-keyring dropped from go.mod, vendor synced.
- README / CONTRIBUTING / AGENTS.md / .agents dev+operations docs now
  point at the new repo; mbse + mascot design docs carry a path note.

Risk: production SPA serving depends on the new pipeline now; rollback
is versioned-image re-up of the old web service from a pre-split
checkout (port 8091). Desktop builds installed before the split still
check dtoro/oikos releases — one manual reinstall, noted in the
oikos-web release notes.

Verification: go vet, make test (race), make generate-check, golangci
(no new findings; baseline down 400→365); post-cutover curls —
localhost:8091 200, /wails/runtime.js 404, outer Caddy 302 Authentik.

web/node_modules/bits-ui/dist/bits/date-range-field/date-range-field.svelte.js

@@ -0,0 +1,202 @@
+import { boxWith, onDestroyEffect, attachRef, DOMContext, } from "svelte-toolbelt";
+import { Context, watch } from "runed";
+import { DateFieldInputState, DateFieldRootState } from "../date-field/date-field.svelte.js";
+import { useId } from "../../internal/use-id.js";
+import { createBitsAttrs, boolToEmptyStrOrUndef } from "../../internal/attrs.js";
+import { createFormatter } from "../../internal/date-time/formatter.js";
+import { removeDescriptionElement } from "../../internal/date-time/field/helpers.js";
+import { isBefore } from "../../internal/date-time/utils.js";
+import { getFirstSegment } from "../../internal/date-time/field/segments.js";
+export const dateRangeFieldAttrs = createBitsAttrs({
+    component: "date-range-field",
+    parts: ["root", "label"],
+});
+export const DateRangeFieldRootContext = new Context("DateRangeField.Root");
+export class DateRangeFieldRootState {
+    static create(opts) {
+        return DateRangeFieldRootContext.set(new DateRangeFieldRootState(opts));
+    }
+    opts;
+    startFieldState = undefined;
+    endFieldState = undefined;
+    descriptionId = useId();
+    formatter;
+    fieldNode = $state(null);
+    labelNode = $state(null);
+    descriptionNode = $state(null);
+    startValueComplete = $derived.by(() => this.opts.startValue.current !== undefined);
+    endValueComplete = $derived.by(() => this.opts.endValue.current !== undefined);
+    rangeComplete = $derived(this.startValueComplete && this.endValueComplete);
+    domContext;
+    attachment;
+    constructor(opts) {
+        this.opts = opts;
+        this.formatter = createFormatter({
+            initialLocale: this.opts.locale.current,
+            monthFormat: boxWith(() => "long"),
+            yearFormat: boxWith(() => "numeric"),
+        });
+        this.domContext = new DOMContext(this.opts.ref);
+        this.attachment = attachRef(this.opts.ref, (v) => (this.fieldNode = v));
+        onDestroyEffect(() => {
+            removeDescriptionElement(this.descriptionId, this.domContext.getDocument());
+        });
+        $effect(() => {
+            if (this.formatter.getLocale() === this.opts.locale.current)
+                return;
+            this.formatter.setLocale(this.opts.locale.current);
+        });
+        /**
+         * Synchronize the start and end values with the `value` in case
+         * it is updated externally.
+         */
+        watch(() => this.opts.value.current, (value) => {
+            if (value.start && value.end) {
+                this.opts.startValue.current = value.start;
+                this.opts.endValue.current = value.end;
+            }
+            else if (value.start) {
+                this.opts.startValue.current = value.start;
+                this.opts.endValue.current = undefined;
+            }
+            else if (value.start === undefined && value.end === undefined) {
+                this.opts.startValue.current = undefined;
+                this.opts.endValue.current = undefined;
+            }
+        });
+        /**
+         * Synchronize the placeholder value with the current start value
+         */
+        watch(() => this.opts.value.current, (value) => {
+            const startValue = value.start;
+            if (startValue && this.opts.placeholder.current !== startValue) {
+                this.opts.placeholder.current = startValue;
+            }
+        });
+        watch([() => this.opts.startValue.current, () => this.opts.endValue.current], ([startValue, endValue]) => {
+            if (this.opts.value.current &&
+                this.opts.value.current.start === startValue &&
+                this.opts.value.current.end === endValue) {
+                return;
+            }
+            if (startValue && endValue) {
+                this.#updateValue((prev) => {
+                    if (prev.start === startValue && prev.end === endValue) {
+                        return prev;
+                    }
+                    return {
+                        start: startValue,
+                        end: endValue,
+                    };
+                });
+            }
+            else if (this.opts.value.current &&
+                this.opts.value.current.start &&
+                this.opts.value.current.end) {
+                this.opts.value.current.start = undefined;
+                this.opts.value.current.end = undefined;
+            }
+        });
+    }
+    validationStatus = $derived.by(() => {
+        const value = this.opts.value.current;
+        if (value === undefined)
+            return false;
+        if (value.start === undefined || value.end === undefined)
+            return false;
+        const msg = this.opts.validate.current?.({
+            start: value.start,
+            end: value.end,
+        });
+        if (msg) {
+            return {
+                reason: "custom",
+                message: msg,
+            };
+        }
+        const minValue = this.opts.minValue.current;
+        if (minValue && value.start && isBefore(value.start, minValue)) {
+            return {
+                reason: "min",
+            };
+        }
+        const maxValue = this.opts.maxValue.current;
+        if ((maxValue && value.end && isBefore(maxValue, value.end)) ||
+            (maxValue && value.start && isBefore(maxValue, value.start))) {
+            return {
+                reason: "max",
+            };
+        }
+        return false;
+    });
+    isInvalid = $derived.by(() => {
+        if (this.validationStatus === false)
+            return false;
+        return true;
+    });
+    #updateValue(cb) {
+        const value = this.opts.value.current;
+        const newValue = cb(value);
+        this.opts.value.current = newValue;
+    }
+    props = $derived.by(() => ({
+        id: this.opts.id.current,
+        role: "group",
+        [dateRangeFieldAttrs.root]: "",
+        "data-invalid": boolToEmptyStrOrUndef(this.isInvalid),
+        ...this.attachment,
+    }));
+}
+export class DateRangeFieldLabelState {
+    static create(opts) {
+        return new DateRangeFieldLabelState(opts, DateRangeFieldRootContext.get());
+    }
+    opts;
+    root;
+    attachment;
+    constructor(opts, root) {
+        this.opts = opts;
+        this.root = root;
+        this.attachment = attachRef(this.opts.ref, (v) => (this.root.labelNode = v));
+    }
+    #onclick = () => {
+        if (this.root.opts.disabled.current)
+            return;
+        const firstSegment = getFirstSegment(this.root.fieldNode);
+        if (!firstSegment)
+            return;
+        firstSegment.focus();
+    };
+    props = $derived.by(() => ({
+        id: this.opts.id.current,
+        "data-invalid": boolToEmptyStrOrUndef(this.root.isInvalid),
+        "data-disabled": boolToEmptyStrOrUndef(this.root.opts.disabled.current),
+        [dateRangeFieldAttrs.label]: "",
+        onclick: this.#onclick,
+        ...this.attachment,
+    }));
+}
+export class DateRangeFieldInputState {
+    static create(opts, type) {
+        const root = DateRangeFieldRootContext.get();
+        const fieldState = DateFieldRootState.create({
+            value: type === "start" ? root.opts.startValue : root.opts.endValue,
+            disabled: root.opts.disabled,
+            readonly: root.opts.readonly,
+            readonlySegments: root.opts.readonlySegments,
+            validate: boxWith(() => undefined),
+            minValue: root.opts.minValue,
+            maxValue: root.opts.maxValue,
+            hourCycle: root.opts.hourCycle,
+            locale: root.opts.locale,
+            hideTimeZone: root.opts.hideTimeZone,
+            required: root.opts.required,
+            granularity: root.opts.granularity,
+            placeholder: root.opts.placeholder,
+            onInvalid: root.opts.onInvalid,
+            errorMessageId: root.opts.errorMessageId,
+            isInvalidProp: boxWith(() => root.isInvalid),
+        }, root);
+        return new DateFieldInputState({ name: opts.name, id: opts.id, ref: opts.ref }, fieldState);
+    }
+}