Block attrs space-separated at end of a text line

_block_attrs now applies a trailing {...} to the block when it ends the
last text line after whitespace (some text {.small}), not only on a line
of its own; a space is what keeps the braces off an image/link ending the
line. Glued-to-text braces stay literal.

docs/design-principles.md

@@ -20,7 +20,7 @@ Pagerite is a single-user CMS/blog. This document records the initial high-level
 - Content is written in **Markdown** with powerful extensions (tables, footnotes, code highlighting, etc.).
 - **Embedded HTML is passed through unfiltered**, including inline scripts and other dynamic content the author wants to post. This is safe by the single-trusted-author assumption above.
 - Renderer: **markdown-it-py** with mdit-py-plugins (footnotes, definition lists, task lists, brace-attributes, admonitions and `::: name` containers — generic `<div class="name">` wrappers (the name may be followed by brace attributes: `::: aside {.right}`), of which `::: aside` floats as a muted side box and `{.margin}` / `::: margin` marks any block a margin note — on all but phone widths they float in the side zone at the article's left (the region the nav sidebar overlays, or the sidebar's own track when the layout reserves one) and the text never moves — and `::: nocols` opts its section out of column layout; tables and strikethrough from the default preset), GitHub-style alerts (`> [!NOTE]` / TIP / IMPORTANT / WARNING / CAUTION, rendered in the admonition callout styling), with `html=True` for raw passthrough, `typographer=True` for SmartyPants-style replacements in body text (curly quotes, `--` / `---` → en / em dashes, `...` → ellipsis, `(c)` → ©, etc.), and `breaks=True` so single line breaks inside paragraphs become `<br>` — including inside blockquotes, where every newline is kept and a blank `>` line starts a new paragraph. Code spans/blocks and raw HTML are left untouched. Fenced code blocks are highlighted server-side with **Pygments** (`nowrap` spans styled by `/_assets/pygments-*.css`, which maps every token class onto the `--code-*` variables; the base stylesheet defines light and dark palette sets resolved via `light-dark()`, so each theme gets the set matching its `color-scheme` and may only retint `--code-bg` to keep the well in the page's color family); a JS copy button appears on hover. Should this prove limiting, we implement our own renderer on top of html5tagger, which we already use for all HTML generation.
-- **Files are content-addressed.** Uploads (`PUT /_api/files/{filename}`) are stored on disk (`<hostname>/files/`, RAM-cached uncompressed + zstd) by content hash — blake3, first 6 bytes hex + original extension — and served immutable from `/_f/{hash}.ext`. Absolute URLs that survive page renames and dedupe identical content; pages no longer own files. An image standing alone in its paragraph becomes a block `<figure>` — with `<figcaption>` when it has a title; images inline with text and raw `<img>` HTML stay plain inline images. Positioning is by attribute classes: `![alt](/_f/….avif "Caption"){.right}` — `{.right}`, `{.left}` float at 30% of the text column (the caption wraps within it; an explicit `width=300` makes the figure shrink-wrap the image instead), `{.margin}` makes it a margin note, floating in the side zone left of the text on all but phone widths, `{.wide}` goes full bleed (viewport edge to edge, or up to the docked editor; the sidebar stacks on top of it); plain attributes like `width=300` work too. The same brace syntax on a block's last line (no blank line between) applies to the whole block: a paragraph ending with `{.wide}` becomes a full-width element that breaks out of the column layout; written on the line after a block it applies to that preceding block — this is how headings, `::: containers` and code fences take classes (a wide code fence goes full bleed like a wide figure). Headings (h1/h2) clear floats, so images never overflow into the next section.
+- **Files are content-addressed.** Uploads (`PUT /_api/files/{filename}`) are stored on disk (`<hostname>/files/`, RAM-cached uncompressed + zstd) by content hash — blake3, first 6 bytes hex + original extension — and served immutable from `/_f/{hash}.ext`. Absolute URLs that survive page renames and dedupe identical content; pages no longer own files. An image standing alone in its paragraph becomes a block `<figure>` — with `<figcaption>` when it has a title; images inline with text and raw `<img>` HTML stay plain inline images. Positioning is by attribute classes: `![alt](/_f/….avif "Caption"){.right}` — `{.right}`, `{.left}` float at 30% of the text column (the caption wraps within it; an explicit `width=300` makes the figure shrink-wrap the image instead), `{.margin}` makes it a margin note, floating in the side zone left of the text on all but phone widths, `{.wide}` goes full bleed (viewport edge to edge, or up to the docked editor; the sidebar stacks on top of it); plain attributes like `width=300` work too. The same brace syntax on a block's last line (no blank line between) applies to the whole block: a paragraph ending with `{.wide}` becomes a full-width element that breaks out of the column layout, and space-separated at the end of a text line (`some text {.small}`) the braces likewise belong to the block — a space is what keeps them off an image or link ending the line, which keep their own directly-attached attrs; text size classes `{.small}` / `{.large}` / `{.huge}` (em-based) work on any block; written on the line after a block it applies to that preceding block — this is how headings, `::: containers` and code fences take classes (a wide code fence goes full bleed like a wide figure). Headings (h1/h2) clear floats, so images never overflow into the next section.
 
 ## Page structure and navigation
 

pagerite/markdown.py

@@ -289,9 +289,11 @@ def _block_attrs(state) -> None:
     """Apply `{.class key=value}` on a block's last line to the block.
 
     The inline attrs plugin only covers attributes right after an image,
-    code span or link; this extends the same brace syntax to whole blocks,
+    code span or link; this extends the same brace syntax to whole blocks.
-    e.g. a paragraph ending with a `{.wide}` line (no blank line between)
+    A paragraph takes them at the end of its last line, either directly
-    gets the `wide` class and thereby breaks out of the column layout.
+    (a trailing `{.wide}` line, no blank line between) or space-separated
+    at the end of the text (`some text {.small}`) — a space means the
+    braces belong to the block, not to an image or link before them.
     A lone `{...}` paragraph applies to the previous block instead (this
     is how headings take attributes, since a heading's next line always
     starts a new paragraph). Runs before the typographer so quotes inside
@@ -302,18 +304,20 @@ def _block_attrs(state) -> None:
         if token.type != "inline" or not token.children:
             continue
         text = token.children[-1]
-        if (
+        if text.type != "text":
-            text.type != "text"
-            or not text.content.startswith("{")
-            or not text.content.endswith("}")
-        ):
             continue
+        m = re.search(r"(\{[^{}]*\})\s*$", text.content)
+        if not m:
+            continue
+        start = m.start(1)
+        if start and not text.content[start - 1].isspace():
+            continue  # glued to the text — literal, or inline attrs
         try:
-            _, attrs = parse_attrs(text.content.strip())
+            _, attrs = parse_attrs(m.group(1))
         except ParseError:
             continue
         standalone = len(token.children) == 1
-        if not standalone and token.children[-2].type != "softbreak":
+        if not standalone and start == 0 and token.children[-2].type != "softbreak":
             continue
         # The target: the enclosing block for a trailing attrs line, or the
         # previous same-level block for a standalone attrs paragraph —
@@ -347,7 +351,14 @@ def _block_attrs(state) -> None:
             tokens[own].hidden = True
             token.children = []
             tokens[i + 1].hidden = True
+        elif start == 0:
+            del token.children[-2:]
         else:
+            # Braces space-separated at the end of a text line: strip them
+            # (a whitespace-only remainder means they were on a line of
+            # their own after all — drop the softbreak too).
+            text.content = text.content[:start].rstrip()
+            if not text.content and token.children[-2].type == "softbreak":
                 del token.children[-2:]