feat: formatted text, a list view, ticket details, public proposals and votes

Formatted text
- Descriptions, comments, replies and release notes render Markdown,
  sanitised with DOMPurify (tested against scripts, handlers and
  javascript: links). A pasted image is uploaded and written as
  ![name](attachment:<id>); the web fetches it with the reader's session,
  so it works on private projects. Every text box has a preview. The
  attachment upload now answers its attachmentId.

List view
- /p/:key/list: every ticket as rows, sortable by any column, filtered by
  text, open/closed, type, priority and assignee; status, priority and
  assignee change in place; bulk edit (the backlog's bar, now shared).

Ticket details
- Reactions on comments (GitHub's eight), for members and viewers.
- Duplicate a ticket: what it says, not where it stands.
- blockedBy: open tickets it waits for (BLOCKS / DEPENDS_ON), worked out
  when reading with one query per board or page; shown on cards, list
  rows and the ticket.

Public proposals
- A public project can take bug reports and ideas from anyone
  (acceptsProposals): POST /api/explore/projects/{project}/proposals and
  the form at /p/:key/proponer. They become tickets labelled «propuesta»,
  opened by TaskStream; a honeypot field and 5 per address every 15
  minutes keep spam out. No e-mail is asked: it would be public.

Votes
- Anyone signed in votes on a public project's tickets, members on a
  private one (voteIssue, PUT/DELETE /api/issues/{issue}/vote): votes and
  voted on each ticket, buttons on the ticket and the roadmap, a column
  in the list. The showcase carries votes and the open proposals.

MCP: vote_issue, duplicate_issue, react_to_comment; listings show
blockers and votes. Docs, Word and PDF updated; chat notifications
(Discord, Slack, Telegram) noted for later.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

libs/web/tracker/presenters/src/lib/pages/issue.page.scss

@@ -445,18 +445,6 @@ a.ts-key {
   margin: 0.5rem 0;
 }
 
-.ts-mention {
-  padding: 0 0.2em;
-  border-radius: 0.25em;
-  background: color-mix(in oklab, var(--ts-brand) 14%, transparent);
-  color: inherit;
-  font-weight: 600;
-}
-
-.ts-mention.is-me {
-  background: color-mix(in oklab, var(--ts-brand) 30%, transparent);
-}
-
 .ts-mentions {
   display: flex;
   flex-wrap: wrap;
@@ -573,3 +561,107 @@ a.ts-key {
   gap: 0.75rem;
   align-items: center;
 }
+
+// Waiting for other tickets: shown next to the key, with links to them.
+.ts-blocked {
+  display: inline-flex;
+  flex-wrap: wrap;
+  gap: 0.375rem;
+  align-items: center;
+  padding: 0.125rem 0.5rem;
+  border-radius: 999px;
+  background: color-mix(in srgb, var(--ts-c-red, #d33) 12%, transparent);
+  color: var(--ts-c-red, var(--ts-ink));
+  font-size: 0.8125rem;
+  font-weight: 600;
+  .ts-key {
+    color: inherit;
+  }
+}
+
+// 👍 2 · 🎉 1 · (+)
+.ts-reactions {
+  display: flex;
+  flex-wrap: wrap;
+  gap: 0.375rem;
+  align-items: center;
+  margin-top: 0.5rem;
+}
+.ts-reaction {
+  display: inline-flex;
+  gap: 0.25rem;
+  align-items: center;
+  // @pi/ui styles every <button> too specifically to override otherwise.
+  min-width: 0 !important;
+  height: auto !important;
+  padding: 0.125rem 0.5rem !important;
+  border: 1px solid var(--ts-line) !important;
+  border-radius: 999px !important;
+  background: var(--ts-surface);
+  color: inherit;
+  font: inherit;
+  font-size: 0.875rem;
+  cursor: pointer;
+  .ts-mono {
+    font-size: 0.75rem;
+  }
+  &.is-mine {
+    border-color: var(--ts-brand) !important;
+    background: color-mix(in srgb, var(--ts-brand) 12%, var(--ts-surface));
+  }
+  &:disabled {
+    cursor: default;
+  }
+}
+.ts-reaction-picker {
+  position: relative;
+  summary {
+    display: inline-grid;
+    place-items: center;
+    width: 1.75rem;
+    height: 1.625rem;
+    border: 1px dashed var(--ts-line-strong, var(--ts-line));
+    border-radius: 999px;
+    color: var(--ts-muted);
+    cursor: pointer;
+    list-style: none;
+    &::-webkit-details-marker {
+      display: none;
+    }
+  }
+}
+.ts-reaction-picker__menu {
+  position: absolute;
+  z-index: 5;
+  bottom: calc(100% + 0.375rem);
+  left: 0;
+  display: flex;
+  gap: 0.125rem;
+  padding: 0.25rem;
+  border: 1px solid var(--ts-line);
+  border-radius: 0.75rem;
+  background: var(--ts-surface);
+  box-shadow: 0 8px 24px rgb(0 0 0 / 14%);
+  button {
+    width: 2rem;
+    min-width: 0 !important;
+    height: 2rem;
+    padding: 0 !important;
+    border: 0 !important;
+    border-radius: 0.5rem !important;
+    background: none;
+    font-size: 1.125rem;
+    cursor: pointer;
+    &:hover {
+      background: color-mix(in srgb, var(--ts-brand) 12%, transparent);
+    }
+  }
+}
+
+.ts-votes {
+  padding: 0.25rem 0.625rem;
+  border: 1px solid var(--ts-line);
+  border-radius: 999px;
+  color: var(--ts-muted);
+  font-size: 0.8125rem;
+}