Add custom fonts: upload WOFF2/WOFF/TTF/OTF files and pick them on the Design tab

Fonts become a file kind of their own (sniffed from the bytes like images,
served inline from /media), and the theme gets custom_font and
custom_heading_font: a chosen file is declared as @font-face and put first
in the stack, the built-in Font / Heading font choice behind it as the
fallback, so there is no "custom" enum value and no invalid state. The
pickers are plain selects with an upload input, no script. Fonts uploaded
before this are reclassified by the migration.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01Sd8UPWrvyYCLj97JexNw3A

1 files changed, 21 insertions, 0 deletions

diff --git a/internal/db/migrations/blog/00010_font_kind.sql b/internal/db/migrations/blog/00010_font_kind.sql
new file mode 100644
index 0000000..cf741e4
--- /dev/null
+++ b/internal/db/migrations/blog/00010_font_kind.sql
@@ -0,0 +1,21 @@
+-- +goose Up
+-- Fonts become a file kind of their own so the design page can offer them.
+ALTER TABLE files DROP CONSTRAINT files_kind_check;
+ALTER TABLE files ADD CONSTRAINT files_kind_check
+    CHECK (kind IN ('image', 'document', 'audio', 'video', 'font', 'archive', 'other'));
+-- Fonts uploaded before this were stored as "other"; the magic bytes tell them
+-- apart (the same signatures the Go sniffer trusts), and substring() reads
+-- only that slice.
+UPDATE files SET kind = 'font', content_type = CASE substring(data from 1 for 4)
+    WHEN '\x774f4632'::bytea THEN 'font/woff2'
+    WHEN '\x774f4646'::bytea THEN 'font/woff'
+    WHEN '\x4f54544f'::bytea THEN 'font/otf'
+    ELSE 'font/ttf' END
+WHERE kind = 'other'
+  AND substring(data from 1 for 4) IN ('\x774f4632'::bytea, '\x774f4646'::bytea, '\x4f54544f'::bytea, '\x00010000'::bytea);
+
+-- +goose Down
+UPDATE files SET kind = 'other', content_type = 'application/octet-stream' WHERE kind = 'font';
+ALTER TABLE files DROP CONSTRAINT files_kind_check;
+ALTER TABLE files ADD CONSTRAINT files_kind_check
+    CHECK (kind IN ('image', 'document', 'audio', 'video', 'archive', 'other'));