Add user bug reporting with admin triage (open/read/resolved)

Turns the /report-bug placeholder into a real form (POST /bug-reports,
optionally attributed to the logged-in user) and adds a "Segnalazioni bug"
section to /admin to view and triage them. A logged-in reporter can also
check their own report's status via GET /bug-reports/mine, since anonymous
submissions have no user to show a history to.

Status is a three-state lifecycle (open -> read -> resolved) rather than a
plain boolean, so an admin can acknowledge a report distinctly from actually
fixing it. The schema went through two migrations because the first one
(add bug_reports table) had already been applied against the running
instance with a `resolved` boolean before the three-state design was
decided, so a follow-up migration backfills it into `status` instead of
rewriting already-applied history.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

migrations/versions/be71fdac734e_replace_bug_reports_resolved_with_a_.py

@@ -0,0 +1,41 @@
+"""replace bug_reports.resolved with a three-state status
+
+Revision ID: be71fdac734e
+Revises: ee8508d98d34
+Create Date: 2026-07-31 15:33:51.780062
+
+"""
+from typing import Sequence, Union
+
+from alembic import op
+import sqlalchemy as sa
+
+
+# revision identifiers, used by Alembic.
+revision: str = 'be71fdac734e'
+down_revision: Union[str, Sequence[str], None] = 'ee8508d98d34'
+branch_labels: Union[str, Sequence[str], None] = None
+depends_on: Union[str, Sequence[str], None] = None
+
+
+def upgrade() -> None:
+    """Upgrade schema, preserving existing rows: resolved=True -> 'resolved', else 'open'.
+
+    'read' has no equivalent in the old boolean, so nothing backfills into it —
+    every previously-open report starts the new lifecycle at 'open', which is
+    correct (nobody had acknowledged it yet)."""
+    op.add_column('bug_reports', sa.Column('status', sa.String(length=16), nullable=True))
+    op.execute("UPDATE bug_reports SET status = CASE WHEN resolved THEN 'resolved' ELSE 'open' END")
+    with op.batch_alter_table('bug_reports') as batch_op:
+        batch_op.alter_column('status', nullable=False)
+        batch_op.drop_column('resolved')
+
+
+def downgrade() -> None:
+    """Downgrade schema. 'read' collapses back into resolved=False — the same loss
+    of information any boolean-from-enum downgrade has."""
+    op.add_column('bug_reports', sa.Column('resolved', sa.BOOLEAN(), nullable=True))
+    op.execute("UPDATE bug_reports SET resolved = (status = 'resolved')")
+    with op.batch_alter_table('bug_reports') as batch_op:
+        batch_op.alter_column('resolved', nullable=False)
+        batch_op.drop_column('status')

migrations/versions/ee8508d98d34_add_bug_reports_table.py

@@ -0,0 +1,41 @@
+"""add bug_reports table
+
+Revision ID: ee8508d98d34
+Revises: 87a0c640355c
+Create Date: 2026-07-31 15:14:14.288552
+
+"""
+from typing import Sequence, Union
+
+from alembic import op
+import sqlalchemy as sa
+
+
+# revision identifiers, used by Alembic.
+revision: str = 'ee8508d98d34'
+down_revision: Union[str, Sequence[str], None] = '87a0c640355c'
+branch_labels: Union[str, Sequence[str], None] = None
+depends_on: Union[str, Sequence[str], None] = None
+
+
+def upgrade() -> None:
+    """Upgrade schema."""
+    # ### commands auto generated by Alembic - please adjust! ###
+    op.create_table('bug_reports',
+    sa.Column('id', sa.Integer(), nullable=False),
+    sa.Column('description', sa.Text(), nullable=False),
+    sa.Column('contact', sa.String(length=256), nullable=True),
+    sa.Column('user_id', sa.Integer(), nullable=True),
+    sa.Column('resolved', sa.Boolean(), nullable=False),
+    sa.Column('created_at', sa.DateTime(), nullable=False),
+    sa.ForeignKeyConstraint(['user_id'], ['users.id'], ),
+    sa.PrimaryKeyConstraint('id')
+    )
+    # ### end Alembic commands ###
+
+
+def downgrade() -> None:
+    """Downgrade schema."""
+    # ### commands auto generated by Alembic - please adjust! ###
+    op.drop_table('bug_reports')
+    # ### end Alembic commands ###